cytochrome-c-t and triphenyltetrazolium

To investigate the role of melatonin in calcium overload-induced heart injury.
 Methods: Thirty-two rats were divided into 4 groups: a control group (Control), a melatonin control group (Mel), a calcium overload group (CaP), and a calcium overload plus melatonin group (Mel+CaP). Isolated Sprague Dawley male rat hearts underwent Langendorff perfusion. Left ventricular developed pressure (LVDP) was calculated to evaluate the myocardial performance. Triphenyltetrazolium chloride staining was used to measure the infarct size of myocardium. Lactate dehydrogenase (LDH) activity in the coronary flow was determined. The expressions of caspase-3 and cytochrome c were determined by Western blot. The pathological morphological changes in myocardial fiber were analyzed by HE staining.
 Results: Compared with the control group, calcium overload significantly induced an enlarged infarct size (P<0.01), accompanied by the disordered arrangement of myocardial fiber, up-regulation of cytochrome c and caspase-3 (P<0.01), and the increased activity of LDH (P<0.01). These effects were significantly attenuated by 10 μmol/L melatonin (P<0.01).
 Conclusion: Melatonin can alleviate calcium overload-induced heart injury.. 目的：观察褪黑素(melatonin，Mel)对大鼠离体心脏急性钙超载损伤的保护作用。方法：将32只大鼠随机分为4组：对照组(Control)、褪黑素组(Mel)、钙反常组(calcium paradox，CaP)和Mel干预钙反常组(Mel+CaP)。大鼠离体心脏行Langendorff灌流，建立钙反常模型；观察左室发展压、心肌梗死面积、乳酸脱氢酶(lactate dehydrogenase，LDH)活性、细胞色素c及caspase-3蛋白的表达变化；HE染色观察心肌纤维形态学变化。结果：与Control组相比，CaP组心肌几乎全部梗死(P<0.01)，冠状动脉流出液中LDH活性显著增加(P<0.01)，心肌纤维排列紊乱，细胞色素c和caspase-3蛋白表达均上调(P<0.01)；Mel(10 μmol/L)干预钙反常组心脏损伤各项指标均明显降低(P<0.01)。结论：Mel可明显减轻大鼠离体心脏急性钙超载诱导的损伤。.

Topics: Animals; Calcium; Caspase 3; Coloring Agents; Cytochromes c; Heart; Heart Injuries; L-Lactate Dehydrogenase; Male; Melatonin; Myocardial Infarction; Myocardium; Perfusion; Rats; Rats, Sprague-Dawley; Tetrazolium Salts

We assessed the validity of monitoring changes in mitochondrial membrane potential (ΔΨ) with a fluorescent probe, JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl benzimidazolo-carbocyanine iodide), for the quantitative evaluation of neonatal hypoxic-ischemic brain injury. Seven-day-old rat pups were subjected to 2h of 8% oxygen following unilateral carotid artery ligation. Brain tissue was obtained for JC-1 staining at 24h after hypoxia ischemia (HI), and the results were compared with those of other simultaneous measurements such as flow cytometry with fluoresceinated annexin V/propidium iodide (PI), terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling (TUNEL) staining, triphenyl tetrazolium chloride (TTC) infarct area and western blot for cytosolic cytochrome c. Flow cytograms of JC-1 showed two distinct sub-populations with different ΔΨ, red with high ΔΨ and green with low ΔΨ, at 24h after HI. This shift of JC-1 fluorescence from red to green indicated a collapse of ΔΨ. The increased percentage of low ΔΨ with JC-1 showed a significant positive correlation with a simultaneous increase in annexin V(+)/PI(+) necrotic cells, TUNEL-positive cells, TTC infarct area and western blot of cytosolic cytochrome c, and negative correlation with annexin V(-)/PI(-) live cells. In summary, low ΔΨ measured with JC-1 was significantly correlated with results from other methods used to assess the extent of brain damage after HI. Therefore, fluorocytometric analysis of ΔΨ with JC-1 might be a sensitive and reliable technique in the quantitative evaluation of neonatal brain injury.

Topics: Animals; Animals, Newborn; Annexin A5; Benzimidazoles; Brain; Brain Infarction; Carbocyanines; Cell Death; Cytochromes c; Disease Models, Animal; Flow Cytometry; Fluorescent Dyes; Hypoxia-Ischemia, Brain; In Situ Nick-End Labeling; Membrane Potential, Mitochondrial; Neurons; Propidium; Rats; Rats, Sprague-Dawley; Tetrazolium Salts; Time Factors

Berberine is an alkaloid derived from herb medicine Coptidis Rhizom. Although there are increasing evidences that berberine exhibits neuroprotective effects against ischemic brain damage, little is known about the mechanism. In this study, we investigated the effect of berberine on ischemic injury in a middle cerebral artery occlusion (MCAO) model. We found that berberine improved neurological outcome and reduced ischemia/reperfusion (I/R)-induced cerebral infarction 48h after MCAO. The protective effect of berberine was confirmed in in vitro study. Berberine protected PC12 cells against oxygen-glucose deprivation (OGD)-induced injury. The results showed that berberine inhibited reactive oxygen species (ROS) generation, and subsequent release of pro-apoptotic factor cytochrome c and apoptosis-inducing factors (AIFs) evoked by OGD. Findings of this study suggest that berberine protects against ischemic brain injury by decreasing the intracellular ROS level and subsequently inhibiting mitochondrial apoptotic pathway.

Topics: Animals; Apoptosis Inducing Factor; Berberine; Brain Infarction; Cell Hypoxia; Cell Survival; Cytochromes c; Disease Models, Animal; Dose-Response Relationship, Drug; Glucose; Infarction, Middle Cerebral Artery; Male; Mice; Mice, Inbred ICR; Neurologic Examination; Neuroprotective Agents; PC12 Cells; Rats; Reperfusion; Tetrazolium Salts

The mechanisms underlying the age-dependent reversal of female cardioprotection are poorly understood and complicated by findings that estrogen replacement is ineffective at reducing cardiovascular mortality in postmenopausal women. Although several protective signals have been identified in young animals, including PKC and Akt, how these signals are affected by age, estrogen deficiency, and ischemia-reperfusion (I/R) remains unknown. To determine the independent and combined effects of age and estrogen deficiency on I/R injury and downstream PKC-Akt signaling, adult and aged female F344 rats (n = 12/age) with ovaries intact or ovariectomy (Ovx) were subjected to I/R using Langendorff perfusion (31-min global-ischemia). Changes in cytosolic (s), nuclear (n), mitochondrial (m) PKC (delta, epsilon) levels, and changes in total Akt and mGSK-3beta phosphorylation after I/R were assessed by Western blot analysis. Senescence increased infarct size 50% in ovary-intact females (P < 0.05), whereas no differences in LV functional recovery or estradiol levels were observed. Ovx reduced functional recovery to a greater extent in aged compared with adult rats (P < 0.05). In aged (vs. adult), levels of m- and nPKC(-delta, -epsilon) were markedly decreased, whereas mGSK3beta levels were increased (P < 0.05). Ovx led to greater levels of sPKC(-delta, -epsilon) independent of age (P < 0.05). I/R reduced p-Akt(Ser473) levels by 57% and increased mGSK-3beta accumulation 1.77-fold (P < 0.05) in aged, ovary-intact females. These data suggest, for the first time, that estrogen alone cannot protect the aged female myocardium from I/R damage and that age- and estrogen-dependent alterations in PKC, Akt, and GSK-3beta signaling may contribute to loss of ischemic tolerance.

Topics: Aging; Animals; Blotting, Western; Body Weight; Coloring Agents; Coronary Circulation; Cytochromes c; Estrogens; Female; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; In Vitro Techniques; Male; Myocardial Ischemia; Myocardial Reperfusion Injury; Oncogene Protein v-akt; Ovariectomy; Protein Kinase C-delta; Protein Kinase C-epsilon; Rats; Rats, Inbred F344; Tetrazolium Salts

It has been reported that immunosuppressant FK506 inhibited ischemic neuronal injury in forebrain ischemia or transient focal cerebral ischemia, but the mechanisms of the neuroprotective effect have not been clarified. In permanent focal cerebral ischemia, we investigated whether FK506 caused remission of brain infarction, and how mechanism was concerned. Male Balb/c mice were subjected to permanent middle cerebral artery (MCA) occlusion. They were treated with 1.0 or 3.0 mg/kg FK506 or vehicle 30 min before ischemia. Infarct volume was assessed by 2,3,5-triphenyltetrazolium chloride (TTC) method after 24 h. Cytochrome c release from mitochondria was evaluated by Western blotting and immunocytochemistry after ischemia. Simultaneously, the immunoreactivity of total and phosphorylated BAD was also studied using immunocytochemistry. We demonstrated that pretreatment with 3.0 mg/kg FK506 salvaged the tissue damage in the infarct rim and significantly reduced infarct volume to 75.5% (P<0.05), and FK506 inhibited cytochrome c release on 6 h after ischemia for Western blot analysis (P<0.05). Immunocytochemical study showed that permanent MCA occlusion increased the amount of cytochrome c and total BAD in the cytosol, but not phosphorylated BAD, in the ischemic core and the infarct rim as early as 1 h after ischemia, and FK506 inhibited the increases in the infarct rim. The results suggest that FK506 may, at least in part, ameliorate tissue damage due to permanent focal cerebral ischemia in the infarct rim through maintaining BAD turnover and inhibiting cytochrome c release from mitochondria.

Topics: Analysis of Variance; Animals; bcl-Associated Death Protein; Blotting, Western; Brain Infarction; Carrier Proteins; Cytochromes c; Dose-Response Relationship, Drug; Immunohistochemistry; Immunosuppressive Agents; Infarction, Middle Cerebral Artery; Male; Mice; Mice, Inbred BALB C; Neocortex; Phosphorylation; Tacrolimus; Tetrazolium Salts; Time Factors