phosphocreatine and Necrosis

In this study a human glioma-derived intracerebral tumor model was analyzed histologically and examined by image-guided 1H NMR spectroscopy. It was shown that histological characteristics such as cellular subpopulation and necrosis of the primary tumor were preserved in the implants. Usually circumscript tumor growth was present with tumor cells invading the surrounding brain parenchyma. It was demonstrated that tumor growth and tumor metabolism could be monitored by image-guided 1H NMR spectroscopy in a longitudinal study. One of the initial changes noticed was the rise of the lactate signal in the tumor region followed by an increase of the choline and a decrease of N-acetyl-aspartate and phosphocreatine signals. Even before tumor invasion in brain adjacent to the central tumor area could be demonstrated by NMR imaging increased lactate and moderately increased choline signals were measured in these regions. By histopathological examination these areas were shown to be infiltrated by single tumor cells. These observations indicate that image-guided 1H NMR spectroscopy could play an important role in the study of brain tumor biology, especially in the case of changing tumor metabolism during growth.

Topics: Animals; Aspartic Acid; Brain Neoplasms; Choline; Energy Metabolism; Glioblastoma; Humans; Lactates; Lactic Acid; Magnetic Resonance Spectroscopy; Mice; Mice, Inbred BALB C; Necrosis; Neoplasm Invasiveness; Neoplasm Transplantation; Phosphocreatine; Rats; Rats, Nude; Skin Neoplasms; Transplantation, Heterologous

The effects of 20th-century stress on the cardiovascular system are reviewed and correlated with experimental animal models. A classic example of such stress is drawn from a study of the aerospace workers at Cape Kennedy who were shown to be exposed to excessive occupational stress. Surprisingly, the usual risk factors did not predict a greater risk, yet the population exhibited a higher incidence of sudden cardiac death and acute myocardial infarction. Acute myocardial necrosis was much more frequently demonstrated than was acute coronary obstruction of any type. Retrospective coroner's studies revealed two types of myocardial necrosis: 1) elongated, thinned or wavy fibers and 2) anomalous contraction bands. Correlation of these clinical observations with experimental data was duplicated in canine models of myocardial infarcion and/or catecholamine-induced necrosis. Catecholamines can lead to irreversible myocardial necrosis but the underlying mechanisms appear to be complex. Extrapolation of the results from the experimental and clinical studies suggests that environmental stress can lead to myocardial necrosis.

Topics: Adenosine Triphosphate; Animals; Catecholamines; Coronary Circulation; Coronary Disease; Death, Sudden; Disease Models, Animal; Environment; Fear; Heart Arrest; Humans; Isoproterenol; Myocardial Infarction; Necrosis; Phosphocreatine; Stress, Psychological; Time Factors

Topics: Adenosine Triphosphatases; Adenosine Triphosphate; Animals; Calcium; Cardiomegaly; Coronary Disease; Digitalis Glycosides; Heart Failure; Hemodynamics; Humans; Myocardium; Myosins; Necrosis; Norepinephrine; Oxygen Consumption; Phosphocreatine; Propranolol

Topics: Adenosine Triphosphate; Angina Pectoris; Animals; Aortic Valve Insufficiency; Cricetinae; Dilatation; Dogs; Endoplasmic Reticulum; Golgi Apparatus; Heart Failure; Humans; Hypoxia; Lactates; Microscopy, Electron; Mitochondria, Muscle; Myocardium; Myofibrils; Necrosis; Oxygen Consumption; Papillary Muscles; Phosphates; Phosphocreatine; Polyribosomes; Rabbits; Rats

Phosphocreatine (PCr) mobilizes high-energy phosphates in cardiac muscles, which is potentially useful as a cardioprotective agent in patients with spinal cord injury (SCI). The cardioprotective effects of PCr on myocardial cell ultrastructure and calcium-sensing receptor (CaSR) expression following high-level spinal cord injury (SCI) were investigated. Healthy adult male Sprague-Dawley (SD) rats (n=54) weighing 250-300 g were subjected to C7 SCI injury by Allen's method with or without treatment by abdominal injection of PCr (200 mg/kg) at 6, 12, 24 or 48 h (SCI + treatment and SCI-only groups, respectively; 6 rats/group/time point). Right apical tissues were sampled 2 h following each time interval. Surgeries without SCI were performed in 6 control rats (sham operation group). Cardiac troponin I (cTnI), serum creatine kinase (CK) and creatine kinase (CK-MB) levels were assessed automatically. Myocardial morphology was examined by transmission electron microscopy (TEM). Quantitative real‑time polymerase chain reaction (qRT-PCR) and western blot analysis were used to determine myocardial tissue calcium-sensing receptor (CaSR) mRNA and protein expression, respectively. Normal myocardial ultrastructure was observed in the sham operation group, while SCI-only groups exhibited progressive and extensive damage to myofibrils, sarcomere structure, mitochondrial membranes and vacuole structures, occasionally accompanied by punctured cell membranes, nuclear chromatin condensation and cavitation. SCI + treatment groups, however, exhibited significantly relieved ultrastructural abnormalities and reduced the levels of CaSR, cTnI, CK and CK-MB mRNA and protein expression at all time intervals (P<0.05). In the SCI rat model, PCr exhibited cardioprotection by relieving myocardial ultrastructural abnormalities and preserving the normal metabolic energy balance, including calcium regulation.

Topics: Acute Disease; Animals; Cardiotonic Agents; Creatine Kinase; Creatine Kinase, MB Form; Male; Myocytes, Cardiac; Necrosis; Phosphocreatine; Rats; Rats, Sprague-Dawley; Receptors, Calcium-Sensing; RNA, Messenger; Spinal Cord Injuries; Time Factors; Troponin I

Increasing energy storage capacity by elevating creatine and phosphocreatine (PCr) levels to increase ATP availability is an attractive concept for protecting against ischaemia and heart failure. However, testing this hypothesis has not been possible since oral creatine supplementation is ineffectual at elevating myocardial creatine levels. We therefore used mice overexpressing creatine transporter in the heart (CrT-OE) to test for the first time whether elevated creatine is beneficial in clinically relevant disease models of heart failure and ischaemia/reperfusion (I/R) injury.. CrT-OE mice were selected for left ventricular (LV) creatine 20-100% above wild-type values and subjected to acute and chronic coronary artery ligation. Increasing myocardial creatine up to 100% was not detrimental even in ageing CrT-OE. In chronic heart failure, creatine elevation was neither beneficial nor detrimental, with no effect on survival, LV remodelling or dysfunction. However, CrT-OE hearts were protected against I/R injury in vivo in a dose-dependent manner (average 27% less myocardial necrosis) and exhibited greatly improved functional recovery following ex vivo I/R (59% of baseline vs. 29%). Mechanisms contributing to ischaemic protection in CrT-OE hearts include elevated PCr and glycogen levels and improved energy reserve. Furthermore, creatine loading in HL-1 cells did not alter antioxidant defences, but delayed mitochondrial permeability transition pore opening in response to oxidative stress, suggesting an additional mechanism to prevent reperfusion injury.. Elevation of myocardial creatine by 20-100% reduced myocardial stunning and I/R injury via pleiotropic mechanisms, suggesting CrT activation as a novel, potentially translatable target for cardiac protection from ischaemia.

Topics: Animals; Cell Line; Creatine; Disease Models, Animal; Energy Metabolism; Glycogen; Heart Failure; Magnetic Resonance Imaging, Cine; Membrane Transport Proteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mitochondria, Heart; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardial Stunning; Myocardium; Necrosis; Oxidative Stress; Phosphocreatine; Time Factors; Up-Regulation; Ventricular Function, Left; Ventricular Remodeling

We report a case, in which quantitative 1H-MR spectroscopy (MRS) was useful for the differentiation between radiation necrosis and a recurrent tumor. The present case is a 44-year-old man who underwent the subtotal removal of a mass lesion in the left frontal lobe. The histological diagnosis was anaplastic oligodendroglioma (WHO grade III). Postoperatively, a fractionated radiotherapy (total 64Gy) and chemotherapy were performed. MRI after the radiotherapy showed no contrast enhancing lesion. MRI, 5 years after the radiotherapy, showed a growing enhancing lesion and a T1 hypointensity lesion without enhancement, both of which indicated a recurrent tumor. MR spectroscopy was performed for the differential diagnosis of these lesions. The spectrum was acquired by the point resolved spectroscopy (PRESS) method by TR/TE=2,000 ms/68 ms, 136 ms, and 272 ms and evaluated with peak pattern and quantification value of metabolite. MRS of the enhancing lesion demonstrated a decrease of the Choline-containing compounds (Cho) concentration, disappearance of N-acetylaspartate (NAA), decrease of Creatine/ Phosphocreatine (t-Cr) and presence of Lipids (Lip) and Lactate (Lac), all of which are characteristic finding of a radiation necrosis. The histological diagnosis of this lesion showed evidence also of radiation necrosis. On the other hand, MRS of the T1 hypointensity lesion without enhancement showed, a marked high peak of the Cho concentration, which is characteristic for a recurrent tumor. The histological findings of this lesion showed a diffuse proliferation of recurrent tumor cells. Quantitative 1H-MRS is a useful tool for the differentiation between radiation necrosis and recurrent tumors.

Topics: Adult; Aspartic Acid; Brain Diseases; Brain Neoplasms; Choline; Creatine; Diagnosis, Differential; Frontal Lobe; Humans; Lactates; Lipids; Magnetic Resonance Spectroscopy; Male; Necrosis; Neoplasm Recurrence, Local; Oligodendroglioma; Phosphocreatine; Radiation Injuries

Differential diagnosis between radiation necrosis and tumor recurrence is important in the clinical management of glioma. Multi-modality imaging including proton magnetic resonance spectroscopy ((1)H-MRS) and positron emission tomography (PET) with L-[methyl-(11)C]methionine (MET) was evaluated. Eighteen patients underwent sequential (1)H-MRS and MET-PET. The expressions of metabolites including choline-containing compounds (Cho), creatine phosphate (Cre), and lactate (Lac) were calculated as the ratios of Cho to Cre (Cho/Cre) and Lac to Cho (Lac/Cho). The uptake of MET was determined as the ratio of the lesion to the contralateral reference region (L/R). The final diagnoses were determined by histological examination and/or follow-up MR imaging and clinical course. The Lac/Cho ratio was 0.63 +/- 0.25 (mean +/- standard deviation) in recurrence (7 cases) and 2.35 +/- 1.81 in necrosis (11 cases). The Lac/Cho ratio was significantly different between the two groups (p < 0.01). Consecutive investigation of (1)H-MRS revealed temporary elevation of Cho in 4 of 9 cases of necrosis, which could be identified as false positive findings for recurrence. Including those cases, MET-PET demonstrated significant difference in the L/R ratio between the two groups (2.18 +/- 0.42 vs. 1.49 +/- 0.35, p < 0.01). According to a 2 x 2 factorial table analysis, the borderline values of Lac/Cho and L/R to differentiate recurrence from necrosis were 1.05 and 2.00, respectively. (1)H-MRS is reliable and accessible for the differentiation of recurrence and necrosis, although the temporary elevation of Cho in the course of necrosis should be recognized. Additional MET-PET imaging can establish the diagnosis.

Topics: Adolescent; Adult; Aged; Biomarkers; Brain; Brain Neoplasms; Carbon Radioisotopes; Choline; Diagnosis, Differential; Fatal Outcome; Female; Glioma; Humans; Lactic Acid; Magnetic Resonance Spectroscopy; Male; Methionine; Middle Aged; Necrosis; Phosphocreatine; Positron-Emission Tomography; Predictive Value of Tests; Radiation Injuries; Radiotherapy; Retrospective Studies; Young Adult

Patients with muscular dystrophy have abnormal cardiac function and decreased high-energy phosphate metabolism. Here, we have determined whether the 8 month old mdx mouse, an animal model of muscular dystrophy, also has abnormal cardiac function and energetics. In vivo cardiac MRI revealed 33% and 104% larger right ventricular end-diastolic and end-systolic volumes, respectively, and 17% lower right ventricular ejection fractions in mdx mice compared with controls. Evidence of left ventricular diastolic dysfunction included 18% lower peak filling rates in mdx mouse hearts. Abnormal cardiac function was accompanied by necrosis and lower citrate synthase activity in the mdx mouse heart, suggesting decreased mitochondrial content. Decreased mitochondrial numbers were associated with 38% lower phosphocreatine concentration, 22% lower total creatine, 36% higher cytosolic free ADP concentration and 1.3 kJ/mol lower free-energy available from ATP hydrolysis in whole isolated, perfused mdx mouse hearts than in controls. Transsarcolemmal creatine uptake was 12% lower in mdx mouse hearts. We conclude that the absence of dystrophin in adult mdx mouse heart, as in the heart of human patient, is associated with right ventricular dilatation, left ventricular diastolic dysfunction and abnormal energy metabolism.

Topics: Adenosine Diphosphate; Adenosine Triphosphate; Animals; Citrate (si)-Synthase; Energy Metabolism; Hydrolysis; Magnetic Resonance Imaging; Male; Mice; Mice, Inbred mdx; Mitochondria, Heart; Muscular Dystrophies; Muscular Dystrophy, Animal; Myocardium; Necrosis; Phosphocreatine; Sarcolemma; Stroke Volume

The physical law of diffusion imposes O2 concentration gradients from the plasma membrane to the center of the cell. The present study was undertaken to determine how such intracellular radial gradients of O2 affect the fate of isolated single cardiomyocytes. In single rat cardiomyocytes, mitochondrial respiration was moderately elevated by an oxidative phosphorylation uncoupler to augment the intracellular O2 gradient. At physiological extracellular O2 levels (2-5%), decreases in myoglobin O2 saturation and increases in NADH fluorescence at the center of the cell were imaged (anoxic cell core) while the mitochondrial membrane potential (DeltaPsim) and ATP levels at the anoxic cell core were relatively sustained. In contrast, treatment with 0.5 mM iodoacetamide (IA) to inhibit creatine kinase (CK) resulted in depletion of both DeltaPsim and ATP at the anoxic cell core. Even at normal extracellular Po2, actively respiring cardiomyocytes developed rigor contracture followed by necrotic cell death. Furthermore, such rigor was remarkably accelerated by IA, whereas cell injury was perfectly rescued by mitochondrial F1Fo inhibition by oligomycin. These results suggest that increases in radial gradients of O2 potentially promote cell death through the reverse action of F1Fo in mitochondria located at the anoxic cell core. However, in the intact cardiomyocyte, the CK-mediated energy flux from the subsarcolemmal space may sustain DeltaPsim at the cell core, thus avoiding uncontrolled consumption of ATP that can lead to necrotic cell death. Mitochondria at the anoxic core can cause necrotic cell death in cardiomyocytes at physiological extracellular Po2.

Topics: Adenosine Triphosphate; Animals; Cell Hypoxia; Cell Respiration; Cell Survival; Creatine Kinase; Diffusion; Enzyme Inhibitors; Iodoacetamide; Membrane Potential, Mitochondrial; Mitochondria, Heart; Myocytes, Cardiac; Myoglobin; NAD; Necrosis; Oligomycins; Oxidative Phosphorylation; Oxygen; Phosphocreatine; Rats; Rats, Sprague-Dawley; Time Factors; Uncoupling Agents

We investigate whether temperature preconditioning (TP), induced by short-term hypothermic perfusion and rewarming, may protect hearts against ischaemic/reperfusion injury like ischaemic preconditioning (IP). Isolated rat hearts were perfused for 40 min, followed by 25 min global ischaemia and 60 min reperfusion (37 degrees C). During pre-ischaemia, IP hearts underwent three cycles of 2 min global ischaemia and 3 min reperfusion at 37 degrees C, whereas TP hearts received three cycles of 2 min hypothermic perfusion (26 degrees C) interspersed by 3 min normothermic perfusion. Other hearts received a single 6 min hypothermic perfusion (SHP) before ischaemia. Both IP and TP protocols increased levels of high energy phosphates in the pre-ischaemic heart. During reperfusion, TP improved haemodynamic recovery, decreased arrhythmias and reduced necrotic damage (lactate dehydrogenase release) more than IP or SHP. Measurements of tissue NAD+ levels and calcium-induced swelling of mitochondria isolated at 3 min reperfusion were consistent with greater inhibition of the mitochondrial permeability transition at reperfusion by TP than IP; this correlated with decreased protein carbonylation, a surrogate marker for oxidative stress. TP increased protein kinase Cepsilon (PKCepsilon) translocation to the particulate fraction and pretreatment with chelerythrine (PKC inhibitor) blocked the protective effect of TP. TP also increased phosphorylation of AMP-activated protein kinase (AMPK) after 5 min index ischaemia, but not before ischaemia. Compound C (AMPK inhibitor) partially blocked cardioprotection by TP, suggesting that both PKC and AMPK may mediate the effects of TP. The presence of N-(2-mercaptopropionyl) glycine during TP also abolished cardioprotection, indicating an involvement of free radicals in the signalling mechanism.

Topics: AMP-Activated Protein Kinases; Animals; Arrhythmias, Cardiac; Coronary Circulation; Hypothermia, Induced; In Vitro Techniques; Ischemic Preconditioning, Myocardial; L-Lactate Dehydrogenase; Male; Mitochondria, Heart; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Mitochondrial Swelling; Multienzyme Complexes; Myocardial Reperfusion Injury; Myocardium; NAD; Necrosis; Oxidative Stress; Perfusion; Phosphocreatine; Phosphorylation; Protein Carbonylation; Protein Kinase C-epsilon; Protein Serine-Threonine Kinases; Protein Transport; Rats; Rats, Wistar; Reactive Oxygen Species; Rewarming; Signal Transduction; Temperature

Antinecrotic activity of 2-ethyl-6-methyl-3 oxipyridin succinate (mexidol) and pentoxifylline (trental) was investigated on 32 mail rats with average body-weight of 170-220 g. Under the influence of mexidol and trental, which were injected 15 min before the insection of skin graft and then once per day during 3 days, necrotized area of skin graft is reduced by 22 and 15%, the amount of lost keranocytes--by 33 and 30%. In skin graft homogenates under the influence of mexidol rises the reduced under ischemia succinate dehydrogenase activity, while under trental influence it does not change. Under the influence of mexidol and trental on third day content of ATP rises by 29,5 and 19,5 %, ADP increases and decreases by 27%, creatinphosphate--by 33 and 21% correspondingly. Trentale improves elasticity of erythrocytes. It is suggested, that positive effect of mexidol on skin graft is conditioned by its ability to activate succinate-dependent detour in oxygen phosphorilation chain of mitochondries and to raise content of ubiquinone, whereas the effect of trental relates with intensification of microcirculation, delivery of oxygen on periphery. That allows recommending combined use of preparations in ischemia of skin.

Topics: Adenosine Diphosphate; Adenosine Triphosphate; Animals; Electron Transport Complex II; Graft Survival; Ischemia; Keratinocytes; Male; Necrosis; Pentoxifylline; Phosphocreatine; Picolines; Rats; Skin; Skin Transplantation; Surgical Flaps

Rat1-T1 and MR1 spheroids represent separate transformed phenotypes originated from the same rat fibroblasts that differ in three-dimensional (3D) growth kinetics, histological structure, and oxygenation status. In the present study, (31)P-NMR spectroscopy of perfused spheroid suspensions was used to investigate cellular energetics relative to 3D growth, development of necrosis, and cell cycle distribution. Both spheroid types were characterized by a remarkably low amount of free (inorganic) phosphate (P(i)) and a low phosphocreatine peak. The ratio of nucleoside triphosphate (NTP) to P(i) ranged between 1.5 and 2.0. Intracellular pH, NTP-to-P(i) ratio, and NTP/cell remained constant throughout spheroid growth, being unaffected by the emergence of oxygen deficiency, cell quiescence, and necrosis. However, a 50% decrease in the ratio of the lipid precursors phosphorylcholine and phosphorylethanolamine (PC/PE) was observed with increasing spheroid size and was correlated with an increased G(1)/G(0) phase cell fraction. In addition, the ratio of the phospholipid degradation products glycerophosphorylcholine and glycerophosphorylethanolamine (GPC/GPE) increased with spheroid diameter in Rat1-T1 aggregates. We conclude that changes in phospholipid metabolism, rather than alterations in energy-rich phosphates, reflect cell quiescence in spheroid cultures, because cells in the inner oxygen-deficient zones seem to adapt their energy metabolism to the environmental conditions before necrotic cell destruction.

Topics: Animals; Cell Division; Cell Line, Transformed; Diffusion Chambers, Culture; Energy Metabolism; Ethanolamines; Fibroblasts; G1 Phase; Glycerylphosphorylcholine; Hydrogen-Ion Concentration; Intracellular Fluid; Magnetic Resonance Spectroscopy; Necrosis; Phosphates; Phosphatidylethanolamines; Phosphocreatine; Phospholipids; Phosphorus Isotopes; Phosphorylcholine; Rats; Rats, Inbred F344; Resting Phase, Cell Cycle; Spheroids, Cellular

Experiments on dogs showed that energostim, a directly acting antihypoxant, injected 15 min after occlusion of the upper one-third of the left descending branch of the interventricular coronary artery produced a pronounced cardioprotective effect. The effect was confirmed by electron microscopy (evaluation the necrotic focus), biochemical tests of the heart and blood, and changes in intracardiac hemodynamics (recovery of systolic and diastolic functions). The cardioprotective effect of energostim greatly surpasses that of routine therapy applied during acute myocardium infarction.

Topics: Animals; Antioxidants; Coronary Disease; Coronary Vessels; Dogs; Heart Ventricles; Hemodynamics; Microscopy, Electron; Myocardial Infarction; Myocardial Ischemia; Myocardium; Necrosis; Phosphocreatine; Time Factors

To add metabolic information during stereotactic biopsy target selection, the authors adopted proton chemical shift imaging (1H CSI)-directed stereotactic biopsy. Currently, proton single voxel spectroscopy (SVS) technique has been reported in stereotactic biopsy. We performed 1H CSI in combination with a stereotactic headframe and selected targets according to local metabolic information, and evaluated the pathological results.. The 1H CSI-directed stereotactic biopsy was performed in four patients. 1H CSI and conventional Gd-enhancement stereotactic MRI were performed simultaneously after the fitting of a stereotactic frame. After reconstructing the metabolic maps of N-acetylaspartate (NAA)/phosphocreatine (Cr), phosphocholine (Cho)/Cr, and Lactate/Cr ratios, focal areas of increased Cho/Cr ratio and Lac/Cr ratios were selected as target sites in the stereotactic MR images.. 1H CSI is possible with the stereotactic headframe in place. No difficulty was experienced performing 1H CSI or making a diagnosis. Pathological samples taken from areas of increased Cho/Cr ratios and decreased NAA/Cr ratios provided information upon increased cellularity, mitoses and cellular atypism, and facilitated diagnosis. Pathological samples taken from areas of increased Lac/Cr ratio showed predominant feature of necrosis.. 1H CSI was feasible with the stereotactic headframe in place. The final pathological results obtained were concordant with the local metabolic information from 1H CSI. We believe that 1H CSI-directed stereotatic biopsy has the potential to significantly improve the accuracy of stereotactic biopsy targeting.

Topics: Adult; Aspartic Acid; Biopsy, Needle; Brain; Brain Neoplasms; Creatine; Diagnosis, Differential; Energy Metabolism; Female; Glioblastoma; Glioma; Humans; Image Processing, Computer-Assisted; Lactic Acid; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; Middle Aged; Necrosis; Phosphocreatine; Phosphorylcholine; Stereotaxic Techniques

It is often difficult to make a correct diagnosis of ring-like enhanced lesions on Gd-enhanced MR brain images. To differentiate these lesions using proton MR spectroscopy (1H-MRS), we retrospectively evaluated the correlation between the 1H-MR spectra and histopathological findings. We evaluated proton MR spectra obtained from the lesions in 45 patients, including metastasis (n = 19), glioblastoma (n = 10), radiation necrosis (n = 7), brain abscess (n = 5), and cerebral infarction (n = 4). The rate of misdiagnosis was found to be lowest at the threshold level of 2.48 for the (choline containing compounds)/(creatine and phosphocreatine) ratio (Cho/Cr) obtained from the whole lesions, which include the enhanced rim and the non-enhanced inner region. That is, the positively predictive values of a Cho/Cr greater than 2.48 for diagnosing metastasis or glioblastoma was 88.9 and 60.0%, respectively, and the positively predictive value of a Cho/Cr less than 2.48 for diagnosing radiation necrosis or cerebral infarction was 71.4 and 100%, respectively. For further differentiating between metastasis and glioblastoma, information about the presence and absence of an N-acetyl-aspartate (NAA) peak and lipid- or lactate-dominant peak was found to be useful. In 73.7% of metastasis cases a lipid-dominant peak was observed in the whole lesion without an NAA peak in the inner region, whereas the same pattern was observed in only 10% of the glioblastoma cases. Correlation with the histopathological findings showed that a high Cho signal is suggestive of neoplasm. Lipid signal in the non-enhanced central region was correlated to necrosis. Lactate signals were often observed in glioblastoma, abscess and sometimes metastasis, presumably reflecting the anaerobic glycolysis by the living cells in the ring-like enhanced rim. Single-voxel proton MR spectroscopy may serve as a potential tool to provide useful information of differentiation of ring-like enhanced lesions that cannot be diagnosed correctly using enhanced MR images alone.

Topics: Adult; Aged; Brain; Brain Abscess; Brain Diseases; Brain Neoplasms; Cerebral Infarction; Choline; Creatine; Diagnosis, Differential; Female; Glioblastoma; Humans; Magnetic Resonance Spectroscopy; Male; Middle Aged; Necrosis; Phosphocreatine; Radiation Injuries; Retrospective Studies

The nuclear enzyme poly (ADP ribose) synthetase (PARS) has been shown to play an important role in the pathogenesis of various forms of ischemia or reperfusion injury and circulatory shock. Recent studies demonstrated that inhibition or genetic inactivation of PARS is beneficial in the early phase of myocardial reperfusion injury. The aim of the present study was to investigate whether inactivation of PARS influences the delayed myocardial necrosis and the production of the proinflammatory cytokine tumor necrosis factor alpha (TNFalpha), the anti-inflammatory cytokine interleukin-10 (IL-10), and the free radical nitric oxide in the late stage of myocardial reperfusion injury. The results demonstrate that genetic disruption of PARS provides marked protection against the delayed myocardial ischemia and reperfusion injury. In addition, in the absence of functional PARS, a suppression of TNFalpha, IL-10, and nitric oxide production was found. These findings provide direct evidence that PARS activation participates in the development of delayed cell injury and delayed mediator production in myocardial reperfusion injury.

Topics: Animals; Blood Pressure; Heart Rate; Hemodynamics; Interleukin-10; Mice; Mice, Knockout; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Necrosis; Peroxidase; Phosphocreatine; Poly(ADP-ribose) Polymerases; Tumor Necrosis Factor-alpha

Controversy exists about correlations between histological tumor grade and magnetic resonance (MR) spectroscopy data. The authors studied single-voxel proton MR spectroscopy as a noninvasive way to evaluate grade of malignancy in intracranial meningiomas.. The authors compared the results of MR spectroscopy with those derived by the MIB-1 staining index (SI) in 29 meningiomas. Proton MR spectroscopy was performed using stimulated echo acquisition and volume-localized solvent-attenuated proton nuclear MR sequences before surgery or other therapy. Twenty-four tumors were histologically benign (13 meningothelial, three fibrous, four transitional, three angiomatous, and one chordoid); four were atypical (Grade II), and one was papillary (Grade III). The mean MIB-1 SI in the benign group was significantly lower than those in the other groups (p = 0.0041). The mean choline-containing compound (Cho)/ creatine and phosphocreatine (Cr) ratios in the benign and nonbenign groups were 2.56+/-1.26 and 7.85+/-3.23, respectively (p = 0.0002). A significant linear correlation was observed between the Cho/Cr ratio and the MIB-1 SI (r0.05 = 0.74, p<0.001). Necrosis was present histologically in four of the five meningiomas classified either as atypical or papillary. Magnetic resonance spectroscopy revealed a methylene signal in these meningiomas that was not detected in benign meningiomas. Of the five meningiomas in which only a lactate signal was observed, two were benign and the MIB-1 SI in these two benign meningiomas was higher than the mean value for the benign group. Alanine, detected in 12 of 30 meningiomas, did not correlate with either tumor grade or Cho/Cr ratio.. Proton MR spectroscopy is a useful diagnostic method for determining the proliferative or malignant potential of meningiomas according to the Cho/Cr ratio. A lactate and/or methylene signal suggests a high-grade tumor.

Topics: Adult; Aged; Aged, 80 and over; Antigens, Nuclear; Biomarkers, Tumor; Brain; Cell Division; Cell Transformation, Neoplastic; Choline; Creatine; Diagnosis, Differential; Energy Metabolism; Female; Humans; Hydrocarbons; Ki-67 Antigen; Lactic Acid; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; Meningeal Neoplasms; Meninges; Meningioma; Methane; Middle Aged; Necrosis; Neoplasm Recurrence, Local; Nuclear Proteins; Phosphocreatine; Prognosis; Reoperation

Few results, and those controversial, have been published on ischemic preconditioning followed by low-flow ischemia. The aim of this study was to assess whether ischemic preconditioning: (1) confers protection against severe underperfusion; and (2) is mediated by mobilization of proglycogen, resulting in increased anaerobic glycolysis and reduced myocardial injury. Isolated rat hearts were retrogradely perfused and subjected to either 25 min low-flow ischemia (0.6 ml/min) followed by 30 min reperfusion (IC; n=5), or the same protocol preceded by two cycles of 5 min no-flow ischemia and 5 min reperfusion (PC; n=7). Additionally, hearts (n=52) were freeze-clamped at different time points throughout the protocol. Preconditioning improved functional recovery (developed force X heart rate in PC hearts: 54 v 21% in IC hearts; P<0.01) and reduced ischemic damage (cumulative release of creatine kinase during reperfusion: 93 v 215 micro/g dry weight; P<0.05). During ischemia and reperfusion, release of adenosine and the sum of purines was smaller in PC hearts (P<0.05), while lactate release was similar in the two groups. PC reduced both macroglycogen and proglycogen by c. 60% (P<0.01) resulting in constant glycogen levels during low-flow ischemia. In contrast, in IC hearts, both fractions decreased by c. 60% during underperfusion (P<0.01). These results demonstrate that: (1) ischemic preconditioning reduces injury due to severe flow reduction; and (2) preconditioning reduced glycogenolysis without affecting anaerobic glycolysis, suggesting increased glucose uptake.

Topics: Adenosine Triphosphate; Animals; Carbohydrate Metabolism; Glucose; Glycogen; In Vitro Techniques; Ischemic Preconditioning, Myocardial; Lactic Acid; Male; Myocardial Contraction; Myocardial Reperfusion Injury; Myocardium; Necrosis; Perfusion; Phosphocreatine; Purines; Rats; Rats, Wistar

Purpose. The purpose of this study was to investigate the relationship between hepatic energy status and liver injury during sepsis, using transgenic mice which express creatine kinase in the liver catalyzing the phosphocreatine/creatine system. Methods. Creatine kinase transgenic mice were fed with normal rodent chow or chow containing 10% creatine for 5 days. Lipopolysaccharide (0.2 mg/kg) combined with d-galactosamine (600 mg/kg) was administered intraperitoneally. Results. Eighty percent of the creatine-fed transgenic mice had survived at 48 h post-d-galactosamine and lipopolysaccharide administration, compared with none of the normally fed transgenic mice. Hepatic phosphocreatine and ATP levels in the normally fed transgenic mice were significantly lower than those in the creatine-fed transgenic mice before and after lipopolysaccharide combined with d-galactosamine was administered. Massive hepatic hemorrhagic necrosis with apoptosis was seen in response to d-galactosamine and lipopolysaccharide in normally fed transgenic mice. These results are consistent with a significant increase in serum aminotransferase at 8 h. In contrast, there were faint necrotic changes in the liver with minimal cellular infiltration in creatine-fed transgenic mice. Conclusions. Maintenance of hepatic ATP levels protects from sepsis-induced liver injury and mortality.

Topics: Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; Brain; Creatine Kinase; Energy Metabolism; Galactosamine; Isoenzymes; Lipopolysaccharides; Liver; Mice; Mice, Transgenic; Necrosis; Phosphocreatine; Rats; Sepsis; Tumor Necrosis Factor-alpha

This study investigated whether both mild and severe hypoxia-ischaemia (HI) caused significant numbers of cells to die by apoptosis in the developing brain in vivo. Newborn piglets were subjected to transient global HI and the fraction of all cells in the cingulate gyrus that were apoptotic or necrotic counted 48 h after resuscitation. The mean (S.D.) proportion of apoptotic cells was 11.9% (6.7%) (sham operated controls 4.1% (2.7%)), while 11.4% (8.4%) were necrotic (controls 0.7% (1.3%)) (P<0.05). Apoptotic and necrotic cell counts were both linearly related to the severity of impaired cerebral energy metabolism measured by magnetic resonance spectroscopy (P<0.05), as shown by: (1) the decline in the ratio of nucleotide triphosphates to the exchangeable phosphate pool during HI; (2) the fall in the ratio of phosphocreatine to inorganic phosphate 8 - 48 h after HI; and (3) an increased ratio of lactate to total creatine at both these times. Thus both apoptosis and necrosis occurred in the cingulate gyrus after both severe and mild HI in vivo in proportion to the severity of the insult.

Topics: Animals; Animals, Newborn; Apoptosis; Brain; Brain Ischemia; Cell Count; Energy Metabolism; Gyrus Cinguli; Hypoxia, Brain; Lactic Acid; Magnetic Resonance Spectroscopy; Necrosis; Phosphocreatine; Swine

To determine whether radiation necrosis can be differentiated from residual/recurrent tumor by proton MR spectroscopy.. We studied the effects of interstitial brachytherapy on the brains of healthy monkeys and in humans with glioblastoma multiforme. The effects of radiation therapy on normal brain tissue in monkeys were assessed with sequential proton MR spectroscopic studies 1 week to 6 months after brachytherapy. Proton MR spectroscopy was also performed in five patients with residual/recurrent glioblastoma multiforme (three of whom had radiation necrosis after brachytherapy), seven patients with newly diagnosed untreated glioblastoma multiforme, and 16 healthy volunteers, who served as a control group.. In monkeys, the ratio of N-acetylaspartate (NAA) to creatine-phosphocreatine (Cr) and the ratio of choline-containing compounds (Cho) to Cr of the reference point were significantly lower 1 week after brachytherapy than before treatment. The ratio of NAA to Cho of the irradiated area tended to be higher 1 week after brachytherapy than before irradiation. These peak metabolic ratios showed characteristic changes 6 months after treatment. In two of three monkeys, lipid signal was elevated 6 months after irradiation. In the clinical study, the ratio of NAA to Cho in the area of radiation necrosis was significantly different from that in glioblastoma multiforme when compared with the contralateral hemisphere after irradiation. In addition, lipid signal was detected in all patients with radiation necrosis.. It might be possible to use proton MR spectroscopy to differentiate radiation necrosis from residual/recurrent glioblastoma multiforme on the basis of comparisons with the contralateral hemisphere after radiation therapy.

Topics: Adult; Animals; Aspartic Acid; Brachytherapy; Brain; Brain Neoplasms; Choline; Cranial Irradiation; Creatine; Diagnosis, Differential; Energy Metabolism; Female; Glioblastoma; Humans; Macaca; Magnetic Resonance Spectroscopy; Male; Middle Aged; Necrosis; Neoplasm Recurrence, Local; Phosphocreatine; Radiation Injuries; Radiation Injuries, Experimental

Phosphorus spin-lattice relaxation times (T1s) were measured in vivo by 31P-nuclear magnetic resonance spectroscopy in tumors from four amelanotic human melanoma xenograft lines grown subcutaneously in BALB/c-nu/nu mice. The T1s were analyzed in relation to tumor volume, fractional tumor water content, and fraction of necrotic tumor tissue. The following resonances were studied: phosphomonoesters (PME), inorganic phosphate (Pi), phosphodiesters (PDE), phosphocreatine (PCr), and nucleoside triphosphates gamma, alpha, and beta (NTP gamma, alpha, and beta). Two different techniques were used to measure the T1s: superfast inversion recovery (SUFIR) and conventional inversion recovery (IR). The SUFIR and IR methods gave similar results. Tumors in the volume range 100-3000 mm3 were studied. The PME, Pi, PDE, and PCr resonances showed significantly longer T1s than the NTP gamma, alpha, and beta resonances at small tumor volumes. The T1s at small tumor volumes also differed significantly between the tumor lines. The T1s either decreased or remained unchanged with increasing tumor volume; the volume-dependence of the T1s differed significantly between the tumor lines but not between the resonances. Calculations based on the T1s measured here indicated that the errors in PCr/Pi and NTP beta/Pi resonance ratios due to partial saturation can vary with tumor volume but are usually < 20% at a repetition time of 2.0 s and < 15% at a repetition time of 3.0 s. There was no correlation between the T1s and fractional tumor water content.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Body Water; Humans; Magnetic Resonance Spectroscopy; Male; Melanoma; Mice; Mice, Inbred BALB C; Mice, Inbred Strains; Mice, Nude; Necrosis; Neoplasm Transplantation; Nucleotides; Phosphates; Phosphocreatine; Phosphorus; Transplantation, Heterologous

Flavone acetic acid and 5,6-dimethyl xanthenone acetic acid have a broad spectrum of anti-tumor activity in mice, and act by stimulating immune cells and inhibiting tumor blood flow, resulting in hemorrhagic necrosis within 24 hrs. To study the evolution of hemorrhagic necrosis, subcutaneous Colon 38 tumors were examined by light and electron microscopy from 30 min to 24 hrs after treatment with these agents, and measurements of tumor energy metabolites made. The results show that both agents cause apoptosis beginning at 30 min, and that by 4 hrs necrosis supervenes, accompanied by rupture of tumor blood vessels. The absence of early endothelial cell damage or thrombosis suggests that vessel rupture, and consequent loss of blood flow and energy metabolite depletion, is caused by loss of extravascular mechanical support by the tumor parenchyma.

Topics: Adenocarcinoma; Adenosine Triphosphate; Animals; Apoptosis; Colonic Neoplasms; Flavonoids; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred DBA; Microscopy, Electron; Necrosis; Phosphocreatine; Xanthenes; Xanthones

Although much has been reported on the energy metabolism of various flaps, at present there is no practical noninvasive and nondestructive method to demonstrate chronologically the changes in phosphate compounds in the same subject during the healing process. A skin island flap was obtained from the dorsal side of the posterior extremities in each of 18 Wistar female rats, and a skin arterial island flap (vein included in the pedicle was ligated and divided) also was obtained from the same area in each of 15 Wistar female rats. Chronological changes of ATP, phosphocreatine, and inorganic phosphate were observed by 31P-MRS (magnetic resonance spectroscopy) using surface coils at various intervals ranging from 2 hours to 1 week after the operation. And pH was calculated based on the chemical shift values. The results showed that the PCr/Pi ratio recovered at 4 to 8 hours postoperatively in the survival group, whereas the PCr/Pi ratio lasted at the low level after the operations in the necrosis group. Magnetic resonance spectroscopy is used extensively in studies of brain, heart, and muscle, but we have found only a few papers dealing with magnetic resonance spectroscopy and none with in vivo study in the field of plastic and reconstructive surgery. Since nuclear magnetic resonance imaging is becoming a "bedside" test in the general hospitals, we consider that the PCr/Pi ratio obtained from 31P-MRS can be an effective, noninvasive, and simple method for clinical use in predicting and observing the viability of flaps at an early stage.

Topics: Adenosine Triphosphate; Animals; Energy Metabolism; Female; Graft Survival; Magnetic Resonance Spectroscopy; Necrosis; Phosphates; Phosphocreatine; Rats; Rats, Wistar; Skin; Surgical Flaps

Prolonged noradrenaline administration to rats in steadily increasing dosages for a period of one to four weeks (cumulative doses 25-35 mg/kg) resulted in the development of focal necrotic areas with abundant collagen fibers and marked hypertrophy of cardiomyocytes. Cellular diameter was higher by 37-44% and extracellular space area by 70-100%. A combination of overcontracted and overdistended sarcomeres in some cardiomyocytes and a twofold rise in serum creatine kinase presumably reflected cellular calcium overload. Myocardial high energy phosphate content was depleted to 50-62% of the control level. The extent of this depletion positively correlated with a decrease in heart rate and cardiac output of the isolated heart. The latter may be attributed to limited left ventricular filling caused by elevated LV diastolic pressure and stiffness. Minimal metabolic and functional changes were observed after lowest noradrenaline dose (5 mg/kg for nine days) that was followed by only moderate depletion of myocardial phosphocreatine content and moderate rise in LV diastolic stiffness. Results suggest that energy-deficient increase in myofibrillar stiffness may form the basis for decreased myocardial distensibility and cardiac pump failure.

Topics: Animals; Cardiomegaly; Creatine Kinase; Dose-Response Relationship, Drug; Energy Metabolism; Female; Heart; Male; Myocardium; Necrosis; Norepinephrine; Phosphocreatine; Rats

This study investigates the potential of in vivo 31P magnetic resonance spectroscopy (MRS) to characterize musculoskeletal tumors and to determine preoperative levels of histological necrosis, which is an important clinical indicator of patient response. Pretherapy MRS was performed on 28 patients with large musculoskeletal tumors: 13 with osteosarcoma, 3 with chondrosarcoma, 5 with malignant fibrous histiocytoma, 1 with desmoid tumor, 1 with Ewing's, 2 with hemangioendothelioma, 1 with myxoid liposarcoma, 1 with synovial cell sarcoma, and 1 with rhabdomyosarcoma. Fifteen patients had follow-up MRS examinations after commencement of chemotherapy (mean of five/patient), eight of whom have now had surgery. Elevated levels of PMEs (P < 0.01), P(i) (P < 0.01), and PDEs (P < 0.02) as well as elevated tumor pH (P < 0.05) were observed in all patients. The synovial cell sarcoma was characterized by high levels of PMEs (> 20%) and low pH (pH 6.76). This contrasted with the spectra obtained from the malignant fibrous histiocytomas which had high levels of PDEs (17 +/- 5%). Reductions in PDE levels postchemotherapy were associated with a high degree of necrosis (> 90%) at surgery, while an increase in PDE levels was associated with a low level of histological necrosis. Likewise, reductions in the ratios PDE/NTP and PDE/PCr and an increase in P(i)/PDE were also associated with a high level of necrosis.

Topics: Adult; Aged; Bone Neoplasms; Chemotherapy, Adjuvant; Ethanolamines; Female; Glycerylphosphorylcholine; Humans; Magnetic Resonance Spectroscopy; Male; Middle Aged; Muscular Diseases; Necrosis; Neoplasm Staging; Neoplasms; Osteosarcoma; Phosphatidylethanolamines; Phosphocreatine; Phosphorus; Phosphorylcholine; Preoperative Care

Skeletal muscle ischemia results in energy depletion and intracellular acidosis. Reperfusion is associated with impaired adenine nucleotide resynthesis, edema formation, and myocyte necrosis. The purpose of these studies was to define the time course of cellular injury and adenine nucleotide depletion and resynthesis in postischemic skeletal muscle during prolonged reperfusion in vivo. The isolated canine gracilis muscle model was used. After 5 h of ischemia, muscles were reperfused for either 1 or 48 h. Lactate and creatine phosphokinase (CPK) release during reperfusion was calculated from arteriovenous differences and blood flow. Adenine nucleotides, nucleosides, bases, and creatine phosphate were quantified by high-performance liquid chromatography, and muscle necrosis was assessed by nitroblue tetrazolium staining. Reperfusion resulted in a rapid release of lactate, which paralleled the increase in blood flow, and a delayed but prolonged release of CPK. Edema formation and muscle necrosis increased between 1 and 48 h of reperfusion (P less than 0.05). Recovery of energy stores during reperfusion was related to the extent of postischemic necrosis, which correlated with the extent of nucleotide dephosphorylation during ischemia (r = 0.88, P less than 0.001). These results suggest that both adenine nucleotide resynthesis and myocyte necrosis, which are protracted processes in reperfusing skeletal muscle, are related to the extent of nucleotide dephosphorylation during ischemia.

Topics: Adenine Nucleotides; Animals; Creatine Kinase; Dogs; Ischemia; Lactates; Lactic Acid; Muscles; Necrosis; Nitroblue Tetrazolium; Organ Size; Phosphocreatine; Regional Blood Flow; Reperfusion Injury; Time Factors

Topics: Adenine Nucleotides; Animals; Blood Glucose; Insulin; Insulin Secretion; Islets of Langerhans Transplantation; Magnetic Resonance Spectroscopy; Necrosis; Phosphates; Phosphocreatine; Phosphorus; Quality Control; Spleen; Swine; Transplantation, Autologous; Transplantation, Heterotopic

The response of tumours to treatment with the cytostatic drugs cisplatin (CDDP) or doxorubicin (DXR) was followed in vivo by 31P NMR spectroscopy. A CDDP-sensitive parent line (IgM-I) and a CDDP-resistant subline (IgM/CDDP) of the IgM-immunocytoma grown s.c. on LOU/M WsL rats were used. Animals from both tumour groups (n = 33) were divided into 3 subgroups: CDDP-treated (1 mg/kg), DXR-treated (10 mg/kg) and control. In 3 out of the 4 treated subgroups where the tumours regressed to less than one half of the initial size, 31P NMR spectroscopy revealed alkaline shifts of 0.31-0.41 pH units at day 4, while the ratio of nucleoside triphosphate to Pi in the tumours, increased continuously to 250-435%. Following CDDP treatment, the 31P NMR spectra of the non-responding IgM/CDDP tumours showed a similar pH increase (0.37 units). The ratio of NTP/Pi showed a temporary decrease to 63 +/- 14% SEM at day 1, which was followed by a recovery to 130 +/- 12% at day 2 and 119 +/- 15% at day 4. The control tumours showed no change in pH and a gradual decrease in the ratio of NTP/Pi. In DXR-treated rats the concentrations of DXR in the immunocytoma tumour and its subline were similar, but in the CDDP-treated rats the IgM-I tumours contained significantly higher levels of platinum than the IgM/CDDP tumours, both measured at 3 and 4 days after administration. The continuous increase in NTP/Pi ratio observed in the responding tumours, is a phenomenon characteristic of tumour regression, while the early temporary decrease in tumour NTP/Pi ratio could be associated with resistance to CDDP. Whether the reported response-specific spectral change applies to other tumour types and other treatment regimens remains to be established.

Topics: Animals; Cisplatin; Doxorubicin; Drug Resistance; Female; Hydrogen-Ion Concentration; Lymphoma; Magnetic Resonance Spectroscopy; Necrosis; Phosphates; Phosphocreatine; Phosphorus; Rats; Rats, Inbred Strains; Ribonucleotides

Phosphorus-31 magnetic resonance spectra were obtained from the RIF-1 tumor in C3H mice before and up to 2 days after various doses of X rays. Parallel studies were performed to measure relative changes in tumor blood perfusion using [14C]iodo-antipyrine and changes in % tumor necrosis using Chalkley's method. Tumor ratios of phosphocreatine to inorganic phosphate (PCr/Pi) and nucleotide triphosphates to inorganic phosphate (NTP/Pi) as well as pH as measured by 31P-MRS increased significantly at most time points after irradiation with doses of 5, 10, and 20 Gy. Tumor blood perfusion was found to significantly improve after a dose of 20 Gy but not after a dose of 2 Gy. Percent tumor necrosis increased to about 3 times its control level at 1 day after a dose of 20 Gy and then declined to about twice its control value at 2 days. The magnitude of the changes in the 31P-MRS parameters makes it unlikely that any of them are entirely due to radiation-induced changes in the radiobiologically hypoxic fraction of these tumors. Changes in the necrotic fraction did not appear to influence the tumor spectra. However, the observed improvement in tumor blood perfusion may have resulted in an increase in oxidative phosphorylation of the whole tumor population as well as a clearance of inorganic phosphate and acid metabolites, so that 31P-MRS changes may indirectly reflect changes in tumor blood perfusion.

Topics: Adenosine Triphosphate; Animals; Antipyrine; Energy Metabolism; Magnetic Resonance Spectroscopy; Male; Mice; Mice, Inbred C3H; Necrosis; Neoplasms, Experimental; Phosphates; Phosphocreatine

In vivo 31P nuclear magnetic resonance spectroscopy was used to examine the bioenergetics of the rat 9L gliosarcoma during untreated growth and in response to chemotherapy with 1,3-bis(2-chloroethyl)-1-nitrosourea. Tumor growth was associated with a decline in the phosphocreatine and nucleoside triphosphate resonances, consistent with an increase in tumor hypoxia during untreated growth. Following chemotherapy with 1,3-bis(2-chloroethyl)-1-nitrosourea (10 mg/kg), tumor levels of phosphocreatine and nucleoside triphosphate rebounded while the level of inorganic phosphate in the tumor declined. Histological comparison of treated and untreated tumor sections 4 days posttreatment showed that the treated tumor had a lower proportion of necrotic cells, a higher proportion of viable cells, and a 5-fold higher level of interstitial space than the control tumor.

Topics: Animals; Carmustine; Energy Metabolism; Extracellular Space; Glioma; Magnetic Resonance Spectroscopy; Necrosis; Nucleotides; Phosphocreatine; Rats

The response of the s.c.-implanted murine mammary carcinoma NU-82 to hyperthermia was followed as a function of time by 31P-nuclear magnetic resonance spectroscopy. Treatment consisted of elevation of the temperature of the tumors to 41-45 degrees C during 15 min. At 18 h after temperatures of up to 42, 43, 44, and 45 degrees C the ratio of ATP/Pi was unchanged, decreased, largely decreased, and approaching zero, respectively. After the higher doses the relative concentrations (in percentage of total phosphate as visible in the nuclear magnetic resonance spectrum) of phosphomonoesters (mainly phosphoethanolamine) and phosphocreatine also decreased in favor of Pi. The changes in phosphodiesters (mainly glycerophosphocholine) correlated linearly with the changes in ATP (r = 0.84, P less than 0.025). Whereas the limited spectral changes after a dose of 43 degrees C were nullified within 24 h, the more drastic changes after a dose of 45 degrees C lasted at least 8 days. The heavier dose not only induced temporary decreases in tumor perfusion like the lower dose (phase 1) but subsequently, unlike the lower dose, resulted in formation of necrosis (phase 2). In the same tumor we found increases in Pi and decreases in ATP and phosphodiesters after radiotherapy with a dose of 20 Gy. Radiotherapy (20 Gy) combined with hyperthermia (44 degrees C) appeared to strengthen these effects and resulted in an improved tumor response (regression).

Topics: Adenosine Triphosphate; Animals; Hyperthermia, Induced; Magnetic Resonance Spectroscopy; Mammary Neoplasms, Experimental; Mathematics; Mice; Mice, Inbred DBA; Necrosis; Phosphocreatine; Phosphorus

The substantia nigra pars reticulata (SNPR) has previously been shown to undergo tissue necrosis following status epilepticus induced by flurothyl in the rat. Even if the rat is ventilated, the SNPR develops necrosis if the epileptic period lasts more than 30 min. Rat brains were frozen in situ after 20 and 60 min of seizure activity and after 60 min of seizure activity followed by 60 min recovery. Labile energy metabolites were then analyzed in the SNPR and in the periaqueductal grey matter (PAG, control region). In the PAG, the metabolite changes during status epilepticus were similar to those reported for cerebral cortex and hippocampus. Measurements showed an unchanged ATP content and energy charge (97% and 98% of control, respectively) and an accumulation of lactate to 9.2 +/- 0.6 mumol/g in the 60-min group. In the PAG, all metabolites measured had returned to control values after 60 min of recovery. In the SNPR, the perturbation of the energy metabolites was much more pronounced during status epilepticus. The concentration of ATP decreased to 75 +/- 3%, the energy charge to 91% +/- 12% and the adenylate pool to 86.7 +/- 5.7% of control. Lactate accumulated to concentrations of 16.1 +/- 1.8 mumol/g and 24.9 +/- 2.3 mumol/g in the 20-min and 60-min groups, respectively. The concentration of lactate was still increased above control after 60 min recovery, whereas the concentration of ATP and the energy charge were lower than control. The findings demonstrate that sustained and intense neuronal activation can cause metabolic disturbance and thereby lead to necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adenosine Triphosphate; Animals; Glucose; Glycogen; Lactates; Lactic Acid; Necrosis; Periaqueductal Gray; Phosphocreatine; Rats; Status Epilepticus; Substantia Nigra

In vivo phosphorus-31 magnetic resonance (MR) spectra were obtained by a surface coil method from rat glioma tissue inoculated subcutaneously in CD Fisher rats, and the effects of photoradiation therapy on tumors were evaluated by sequentially observing spectral changes. In the control group, the nucleoside triphosphate (NTP) and phosphomonoester peaks were large, the phosphocreatine peak was small, and the inorganic phosphate (Pi) peak was intermediate. In all eight cases in the group in which a dose of 10 mg/kg of hematoporphyrin derivatives (HpD) was given before photoirradiation, NTP peaks decreased, and the Pi peak increased remarkably within 1 hour after the 60-minute white-light irradiation. Spectral changes were observed before histologic changes were apparent. Histologic examinations 3 days after irradiation showed extensive necrosis in the tumor tissue. With preinjection of 5 mg/kg HpD, three of the eight cases showed spectrum changes after the irradiation. No spectrum changes were observed in the group with preinjection of 2.5 mg/kg. In vivo P-31 MR spectra measurements are useful not only to investigate the energy metabolism of tumor tissue in vivo but also to evaluate the effects of photoradiation therapy on tumors.

Topics: Animals; Brain Neoplasms; Energy Metabolism; Evaluation Studies as Topic; Glioma; Hematoporphyrin Photoradiation; Magnetic Resonance Spectroscopy; Necrosis; Phosphates; Phosphocreatine; Photochemotherapy; Purine Nucleotides; Rats

This study compares blood versus crystalloid cardioplegia in restoring contractile function, and high-energy phosphate and tissue water content in a myocardial segment after 1 hour of coronary artery occlusion. Anesthetized dogs underwent instrumentation with the chest open to measure left ventricular and aortic pressures, and systolic shortening in the myocardium perfused by the left anterior descending coronary artery (LAD) was measured with ultrasonic crystals. In 21 dogs, the LAD was occluded for an hour, thereby replacing systolic shortening with passive lengthening averaging -28.7 +/- 6.2% of control shortening in both groups. The dogs were then placed on total bypass, and arrest was achieved with multidose crystalloid (N = 10) or blood cardioplegia (N = 11). The ligatures were released just prior to the second infusion of cardioplegic solution. Postischemic subendocardial levels of adenosine triphosphate were comparably depleted with crystalloid and blood cardioplegia (55.2% and 44.0%, respectively, of control). Subendocardial increases in water content were similar for crystalloid (3.62%) and blood (3.16%) cardioplegia. Recovery of segmental shortening was significantly greater with blood than crystalloid cardioplegia (31.5 +/- 8.2% versus 4.9 +/- 6.6% of control, respectively). We conclude that the composition and the delivery of blood cardioplegia used in this study restore greater postischemic function than crystalloid cardioplegia in acute evolving myocardial infarction.

Topics: Adenosine Triphosphate; Animals; Body Water; Coronary Circulation; Coronary Disease; Dogs; Evaluation Studies as Topic; Heart Arrest, Induced; Myocardial Contraction; Myocardium; Necrosis; Phosphocreatine; Postoperative Period; Potassium; Potassium Compounds

Reocclusion after successful coronary reperfusion occurs in 15 to 35% of patients receiving thrombolytic therapy for acute myocardial infarction. The present study was designed to simulate the clinical situation of reocclusion and determine whether verapamil might be effective in reducing myocardial necrosis and preserving high energy phosphates in this setting. Pentobarbital-anesthetized, open chest dogs underwent occlusion of the left anterior descending coronary artery for 2 hours followed by 1 hour of reperfusion and a further 4 hours of coronary artery occlusion. Treatment with verapamil (intravenous bolus dose of 0.2 mg/kg body weight followed by infusion of 0.56 +/- 0.14 mg/kg per h) was begun 1 hour after occlusion and infusion was continued for the remainder of the experiment. The dose of verapamil was adjusted to lower mean arterial pressure to approximately 90 mm Hg. The area at risk was determined by intraatrial injection of monastral blue dye and the area of necrosis was assessed by triphenyltetrazolium chloride staining. In vivo myocardial needle biopsy for determination of adenosine triphosphate and creatine phosphate was performed at the end of the experiment. The area of the left ventricle at risk was similar in both groups (control [n = 8], 20.2 +/- 1.6% versus verapamil-treated [n = 9], 23.1 +/- 2.9%; p = NS). The area of necrosis expressed as a percent of the area at risk was reduced in the verapamil-treated group compared with the control group (43.3 +/- 5.0% versus 63.1 +/- 6.8%, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adenosine Triphosphate; Animals; Blood Pressure; Coronary Circulation; Coronary Disease; Dogs; Female; Male; Myocardium; Necrosis; Phosphocreatine; Recurrence; Verapamil

In previous studies nifedipine has been shown to limit infarct size during 24 h of regional ischemia in the dog. Using a closed chest embolization procedure, autoradiographic (141-cerium at onset of ischemia) microsphere risk zone analysis and tetrazolium staining, the ability of nifedipine to influence collateral flow, energy metabolism and infarct size over 48 h was assessed in the dog. A second microsphere (46-scandium), which did not interfere with the autoradiography, was given after 48 h of ischemia to allow temporal changes in flow to be assessed. Transmural biopsies, taken after 48 h from non-ischemic tissue, ischemic tissue which had become necrotic and ischemic tissue which had survived (tetrazolium-positive tissue within the risk zone) were assayed for flow, adenosine triphosphate (ATP) and creatine phosphate (CP). The results indicate: nifedipine may still afford some small degree of protection up to 48 h of elapsed ischemia, (infarct size as a percent of risk zone size was 86.1 +/- 3.0 in control vs 70.4 +/- 4.5 in drug group (p less than 0.025 n = 9 in each group), 'salvage' in both the control and the nifedipine-treated groups was predominantly subepicardial and in the transmural plane. The extent and location of salvage and necrosis was determined by the epicardial to endocardial distribution of collateral flow. In tissue which was destined to necrosis (mainly in the subendocardium) collateral flow at the onset of ischemia (7.2 +/- 1.2% relative to surrounding non-ischemic tissue) did not increase over 48 h (8.0 +/- 1.4) whereas in tissue which was 'salvaged' (mainly in the subepicardium) flow was greater (27.4 +/- 3.2%) at onset of ischemia) and increased substantially (to 64.6 +/- 5.9%) over 48 h; nifedipine does not increase the amount of flow per g of tissue in salvaged tissue but rather it may increase the amount of tissue receiving sufficient flow to promote salvage; it follows that in nifedipine-treated animals more flow is delivered to the ischemic zone; tissue ATP and CP parallel flow and the results support the concept of a critical threshold of flow (approx. 25% at onset of ischemia) below which tissue eventually deteriorates to necrosis and above which tissue is likely to amenable to salvage. However, for sustained survival this flow level must eventually increase to above 40-50%. In conclusion, while nifedipine can achieve a substantial delay in the onset of tissue necrosis, for sustained salvage there must be early and substa

Topics: Adenosine Triphosphate; Animals; Collateral Circulation; Coronary Circulation; Dogs; Electrocardiography; Female; Male; Microspheres; Myocardial Infarction; Necrosis; Nifedipine; Phosphocreatine

Topics: Adenosine Triphosphate; Animals; In Vitro Techniques; Myocardial Contraction; Myocardial Infarction; Myocardium; Necrosis; Phosphocreatine; Platelet Aggregation; Rabbits; Swine; Swine, Miniature

Reperfusional damage refers to the serious structural, functional, and metabolic derangements commonly observed during restoration of coronary circulation following cardiopulmonary bypass. Damage is believed to result from ischemic injury incurred during aortic cross-clamping and unmasked in the recovery period and/or certain metabolic processes activated during postischemic reperfusion. It has been postulated that reperfusional damage can be minimized or eliminated if normal myocardial metabolic parameters can be maintained or restored before the initiation of reperfusion. Studies have tested a variety of cardioplegic solution compositions and administration modes. However, much controversy exists over the different methods. We have tested the hypothesis that improved myocardial protection during cardioplegia can prevent reperfusional damage and investigated the possibility of achieving optimal myocardial protection. Elective cardiac arrest was induced in isolated perfused rat hearts, under working conditions reported previously. We tested two arresting temperatures (8 degrees C and 28 degrees C), three infusion frequencies (single, double, and multiple dose), and different combinations of cardioplegic additives with demonstrated benefits (glucose, adenosine, creatine, and albumin). Metabolic and hemodynamic functions were used to evaluate the protection of the ischemic myocardium. Glucose (0.5%) and adenosine (1 mmol/L) provided clear benefits under all experimental conditions. Double-dose cardioplegia at 8 degrees C also surpassed the single- and multiple-dose groups. When oxygenated cardioplegic solution containing glucose and adenosine was reinfused for 1 minute after 30 minutes of cross-clamping, no measurable changes were detected after ischemic arrest, as compared with normal hearts. Reperfusional damage was eliminated by this procedure. We concluded that an optimal condition for myocardial preservation during elective cardiac arrest in our model was established.

Topics: Adenosine; Adenosine Triphosphate; Animals; Cardiopulmonary Bypass; Coronary Circulation; Glucose; Heart; Heart Arrest, Induced; Lactates; Lactic Acid; Male; Myocardium; Necrosis; Perfusion; Phosphocreatine; Postoperative Complications; Rats; Rats, Inbred Strains; Temperature

Topics: Adenosine Triphosphate; Animals; Arterial Occlusive Diseases; Coronary Circulation; Coronary Disease; Dogs; Hemodynamics; Myocardial Contraction; Myocardial Infarction; Myocardium; Necrosis; Perfusion; Phosphocreatine; Time Factors

Topics: Adenine Nucleotides; Adenosine Triphosphate; Animals; Brain Chemistry; Coronary Disease; Creatine; Necrosis; Phosphocreatine; Rats; Rats, Inbred Strains; Stress, Physiological

Topics: Adenosine Triphosphate; Adult; Coronary Artery Bypass; Coronary Disease; Creatine Kinase; Glycogen; Hemodynamics; Humans; Hypothermia, Induced; Isoenzymes; Mitochondria, Heart; Myocardium; Necrosis; Phosphocreatine

The purpose of this study was to determine whether or not the biochemical, functional, and ultrastructural abnormalities produced by brief temporary coronary occlusions (unassociated with necrosis) ever resolve and, if so, when they do. Anesthetized open-chest dogs were subjected to 15 min of coronary artery occlusion followed by 72 hr, 7 days, or 14 days of reperfusion. Serial in vivo myocardial biopsies were performed for measurement of ATP and for ultrastructural analysis. Regional function was evaluated by sonomicrometry. Mean (+/- SEM) myocardial ATP concentration was 36.6 +/- 1.2 nmol/mg of cardiac protein in nonischemic subendocardium and 18.9 +/- 1.5 in ischemic subendocardium after 15 min of ischemia. ATP remainede performed for measurement of ATP and for ultrastructural analysis. Regional function was evaluated by sonomicrometry. Mean (+/- SEM) myocardial ATP concentration was 36.6 +/- 1.2 nmol/mg of cardiac protein in nonischemic subendocardium and 18.9 +/- 1.5 in ischemic subendocardium after 15 min of ischemia. ATP remainede performed for measurement of ATP and for ultrastructural analysis. Regional function was evaluated by sonomicrometry. Mean (+/- SEM) myocardial ATP concentration was 36.6 +/- 1.2 nmol/mg of cardiac protein in nonischemic subendocardium and 18.9 +/- 1.5 in ischemic subendocardium after 15 min of ischemia. ATP remained depressed in the reperfused previously ischemic subendocardium at both 90 min (68% of nonischemic value) and 72 hr (78% of nonischemic value) but returned to normal at 7 days. Regional systolic function and cardiac ultrastructural abnormalities required 7 days for full recovery. Histologic and histochemical analysis did not reveal necrosis at any time. Therefore, biochemical, functional, and ultrastructural abnormalities induced by brief periods of transient coronary occlusion not associated with necrosis do resolve completely but the recovery period is prolonged.

Topics: Adenosine Triphosphate; Animals; Blood Pressure; Coronary Disease; Dogs; Heart; Heart Rate; Kinetics; Microscopy, Electron; Myocardium; Necrosis; Perfusion; Phosphocreatine

1. The fatty acid composition of cardiac membrane lipids is influenced by age, sex, diet and other factors. 2. The relative amounts of various polyunsaturated fatty acids in cardiac lipids influence markedly the development of myocardial necrosis and mortality following overstimulation with isoproterenol. 3. The availability and metabolism of arachidonic acid may play an important role in regulation of cardiac metabolism.

Topics: Adenosine Triphosphate; Age Factors; Animals; Arachidonic Acids; Dietary Fats; Energy Metabolism; Fatty Acids; Female; Humans; Isoproterenol; Lipid Metabolism; Lipids; Male; Membranes; Myocardial Infarction; Myocardium; Necrosis; Phosphocreatine; Rats; Sex Factors

The crucial point in the pathogenesis of isoproterenol-induced myocardial necrotization is an abundant intracellular Ca accumulation leading to high energy phosphate exhaustion. Accordingly, in the early stage of the isoproterenol-induced necrotization process, the onset of ATP and creatine phosphate breakdown strictly parallels the acute Ca gain. In this type of necrosis, the Mg losses from the myocardium appear as a concomitant phenomenon. The hearts can be protected against the deleterious Ca overload and necrotization by increasing the plasma concentration of Mg, K, or H ions in order to counterbalance Ca according to the ration (see article). On the other hand, if Mg, K, or H ion concentrations are too low, isoproterenol-induced Ca uptake and myocardial lesions are potentiated.

Topics: Adenosine Triphosphate; Animals; Calcium; Cardiomyopathies; Dose-Response Relationship, Drug; Hydrogen-Ion Concentration; Isoproterenol; Magnesium; Myocardium; Necrosis; Phosphocreatine; Potassium; Rats

Skeletal and heart muscle fibers undergo severe functional and structural alterations, resulting in necrotization as soon as extracellular Ca ions penetrate excessively into the sarcoplasm, so that the capacities of the Ca binding or extrusion processes become insufficient. In mechanically injured skeletal muscle fibers, this necrotization process begins in the neighborhood of the membrane lesion where a large Ca inward transport takes place. Accordingly, elimination of Ca from the Ringer solution or an outward electric current which blocks the influx of extracellular Ca prevents the onset of necrotization, whereas additional Ca or an inward electric current which augments the influx of Ca potentiates the course of degradation. The crucial reaction in the production of necroses in skeletal and heart muscle fibers is a high energy phosphate deficiency which results (a) from excessive activation of Ca-dependent intracellular ATPases, and (b) from Ca-induced mitochondrial destruction. This applies especially to myocardial fiber damage caused by large doses of beta-adrenergic catecholamines such as isoproterenol. The number and size of the isoproterenol-induced cardiac lesions are obviously determined by the extent and, particularly, by the duration of the Ca-mediated high energy phosphate penury. Substances which sensitize the myocardium to catecholamine-induced necrotization (9-alpha-fluorocortisol, dihydrotachysterol, NaH2PO4) act by potentiating intracellular Ca overload and high energy phosphate breakdown. Conversely, verapamil D 600, and other Ca-antagonistic compounds protect the structural integrity of the heart muscle fibers by restricting transmembrane Ca influx and, consequently, ATP and creatine phosphate exhaustion.

Topics: Adenosine Triphosphate; Animals; Calcium; Cardiomyopathies; Heart; Humans; Isoproterenol; Muscles; Necrosis; Phosphocreatine; Rats; Verapamil

Topics: Adenosine Triphosphate; Animals; Glucose; Glycogen; Heart; Heart Diseases; Hypoxia; Isoproterenol; Lactates; Male; Myocardium; Necrosis; Perfusion; Phosphocreatine; Rats; Time Factors

Topics: Adenosine Diphosphate; Adenosine Monophosphate; Adenosine Triphosphate; Animals; Blood Glucose; Blood Pressure; Creatine; Glycogen; Hindlimb; Ischemia; Lactates; Male; Muscles; Necrosis; Phosphocreatine; Rats; Time Factors; Tourniquets

Topics: Animals; Creatine Kinase; Diaphragm; Muscles; Muscular Diseases; Necrosis; Phosphocreatine; Quinolines; Rabbits

Topics: Adenine Nucleotides; Animals; Body Weight; Cholesterol; Creatine; Glycogen; Heart; Isoproterenol; Lactates; Myocardium; Necrosis; Organ Size; Phosphocreatine; Phospholipids; Propranolol; Rats; Triglycerides

Topics: Animals; Calcinosis; Clinical Enzyme Tests; Creatine Kinase; Cricetinae; Genetics; Heart Diseases; Mesocricetus; Muscular Dystrophies; Necrosis; Pathology; Phosphocreatine; Research