piperidines and Vasospasm--Intracranial

The efficacy and safety of a new platelet-activating factor receptor antagonist, E5880, were investigated for preventing cerebral vasospasm after subarachnoid hemorrhage (SAH) in 71 patients with SAH who underwent surgery for ruptured aneurysms within 3 days. Intravenous E5880 administration (300 micrograms or 1200 micrograms twice daily) was begun within 4 days and continued for 14 days. The incidence of symptomatic vasospasm, low-density area on computed tomography, and angiographic vasospasm was lower than in placebo groups in previous studies. Clinical outcome was favorable compared with previous studies. No clinically important adverse events were observed. These results suggest that E5880 is safe and effective in the treatment of patients with cerebral vasospasm due to SAH.

Topics: Adult; Aged; Aneurysm, Ruptured; Brain; Clinical Protocols; Dose-Response Relationship, Drug; Female; Humans; Incidence; Injections, Intravenous; Intracranial Aneurysm; Male; Middle Aged; Piperidines; Platelet Activating Factor; Platelet Membrane Glycoproteins; Pyridinium Compounds; Radiography; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Subarachnoid Hemorrhage; Treatment Outcome; Vasospasm, Intracranial

Under physiologic conditions, losartan showed a dose-dependent antagonistic effect to the endothelin-1 (ET-1)-mediated vasoconstriction. This reduced vasoconstriction was abolished after preincubation with an endothelin B

Topics: Angiotensin II Type 1 Receptor Blockers; Angiotensins; Animals; Basilar Artery; Disease Models, Animal; Endothelin Receptor Antagonists; Endothelin-1; Losartan; Male; Oligopeptides; Peptides, Cyclic; Piperidines; Rats; Rats, Sprague-Dawley; Receptor Cross-Talk; Subarachnoid Hemorrhage; Vasoconstriction; Vasodilation; Vasospasm, Intracranial

Delayed cerebral vasospasm is a main cause of morbidity and mortality as well as poor outcome in patients following aneurysmal subarachnoid hemorrhage (SAH). In this study, the effect of the bronchodilator KMUP-3 (7-[2-[4-(4-nitrobenzene)piperazinyl]ethyl]-1,3-dimethylxanthine) on basilar artery narrowing, neurological outcome, and expression of rhoA/rho kinase II (ROCKII), rhoA, and protein kinase C (PKC) γ proteins were evaluated in a rat model of SAH. SAH was induced by double injection of autologous blood into the cistern magna on days 0 and 3. KMUP-3 was administered (0.3 mg/kg/day) by osmotic minipumps implanted subcutaneously (beginning day -3 in pretreatment group and at 1 h after the initiation of the first autologous blood injection in the treatment group). Neurological outcome was assessed by ambulation and placing/stepping reflex responses at 48 h after the second injection of autologous blood. Tissue morphology and protein expression were conducted on day 7 post-day 0 injection. Both KMUP-3 treatment regimens significantly improved neurological outcome and completely attenuated basilar artery narrowing as well as reduced the enhancement of ROCKII, rhoA, and PKCγ protein expression in rats subjected to SAH, compared with normal and untreated SAH rats. These results suggest that KMUP-3 may be a novel agent for the treatment of cerebral vasospasm following SAH.

Topics: Animals; Bronchodilator Agents; Disease Models, Animal; Drug Interactions; Gene Expression Regulation; Hemodynamics; Locomotion; Male; Neurologic Examination; Piperidines; Protein Kinase C; Rats; Rats, Sprague-Dawley; Reflex; rho-Associated Kinases; rhoA GTP-Binding Protein; Subarachnoid Hemorrhage; Vasospasm, Intracranial; Xanthines

Alterations in the activity of vascular K channels are commonly associated with abnormalities in cerebral vascular function after subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage-induced vasospasm remains incompletely understood; nevertheless, activation of K channels may be of benefit in relieving spastic constriction. This study was to examine whether the vasodilators KMUP-1 and pinacidil, a KATP-channel opener, have the ability to prevent SAH-induced vasospasm via the large-conductance Ca-activated K (BKCa) channels in cerebral arteries. Rats were divided into four groups including sham-operated, SAH, KMUP-1 treated, and pinacidil treated. Subarachnoid hemorrhage rats were induced by injecting autologous blood into cisterna magna, and then KMUP-1 or pinacidil (1 mg/kg) was injected intraperitoneally 1 and 24 h after SAH. Behavioral tests were assessed on day 2 after SAH before the rats were killed. Cerebral myocytes were enzymatically isolated from rat basilar arteries and used to monitor BKCa-channel activities. In isolated basilar arteries, KMUP-1-treated and pinacidil-treated rats showed normalized vascular reactivity. In whole-cell recordings, BKCa currents were attenuated in SAH rats compared with sham-operated rats. In inside-out patches, the conductance and voltage sensitivity of single BKCa-channels were unchanged among the four groups. In contrast, SAH rats showed markedly decreased BKCa-channel activity and β1-subunit expression associated Ca sensitivity that was further confirmed by immunofluorescence staining and Western blotting. Subarachnoid hemorrhage-induced deficits in motor function and BKCa-channel inhibition were improved by KMUP-1-treated and pinacidil-treated rats. In addition, SAH appears to modify BKCa-channel calcium sensitivity. KMUP-1 and pinacidil prevent SAH-induced vasospasm at least in part by the restoration of BKCa-channel activities.

Topics: Animals; Basilar Artery; Down-Regulation; Large-Conductance Calcium-Activated Potassium Channels; Male; Muscle, Smooth, Vascular; Pinacidil; Piperidines; Psychomotor Performance; Rats; Rats, Sprague-Dawley; Subarachnoid Hemorrhage; Vasoconstriction; Vasodilator Agents; Vasospasm, Intracranial; Xanthines

The 53-year-old female patient had suffered massive subarachnoid bleeding due to rupture of left-localized aneurysm of the anterior communicant artery. Following the neurosurgical intervention, deterioration of consciousness related to strong vasospasm occurred. Cerebral CT examination was performed, showing a 0.5 cm ischaemic lesion of the left hippocampal fornix. Due to intensive therapy, the patient recovered gradually, however considerable short-time memory deficit and severe anterograde amnesia remained. Admission of the patient in psychiatric care 5 weeks after the operation was necessary since acute deterioration had been added to memory disturbance and anterograde amnesia. Clinical features included severe short-time memory deficit, continuous and severe anterograde amnesia, disorientation, alterations of verbal fluency and abstraction. The amnesic syndrome was probably related to the hippocampal damage, but considering the development of cognitive deficits, cerebral CT was performed again, which verified internal hydrocephalus. A ventriculo-peritoneal shunt has been implanted and the patient was re-admitted in psychiatry care because of her memory deficit, anterograde amnesia and disorientation. Thereafter, low doses of citalopram and donepezil therapy was started together with temporarily used antipsychotic medication (risperidone). Gradual, but continuous improvement of memory and cognitive function could be detected, with total recovery after one year. The deficits in long- and short-term memory, orientation and cognition were totally restored.

Topics: Amnesia, Anterograde; Citalopram; Donepezil; Female; Fornix, Brain; Humans; Indans; Intracranial Aneurysm; Korsakoff Syndrome; Middle Aged; Neurosurgical Procedures; Nootropic Agents; Piperidines; Risperidone; Rupture, Spontaneous; Subarachnoid Hemorrhage; Vasospasm, Intracranial

Topics: Adult; Anesthesia, Conduction; Anesthesia, General; Anesthesia, Obstetrical; Brain Edema; Cesarean Section; Contraindications; Emergencies; Female; Hemodynamics; Humans; Infant, Newborn; Intracranial Arteriovenous Malformations; Male; Piperidines; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Trimester, Third; Remifentanil; Respiratory Distress Syndrome, Newborn; Subarachnoid Hemorrhage; Vasospasm, Intracranial; Vertebral Artery

This study was undertaken to demonstrate the role of the RhoA/Rho kinase pathway in endothelin-1 (ET-1)-induced contraction of the rabbit basilar artery. Isometric tension and Western blot were used to examine ET-1-induced contraction and RhoA activation. The upstream effect on ET-1-induced RhoA activity was determined by using ET(A) and ET(B) receptor antagonists, protein kinase C (PKC), tyrosine kinase, and phosphatidylinositol-3 kinase inhibitors. The downstream effect of ET-1-induced contraction and RhoA activity was studied in the presence of the Rho kinase inhibitor Y-27632. The effect of Rho kinase inhibitor on ET-1-induced myosin light chain (MLC) phosphorylation was investigated by using urea-glycerol-PAGE immunoblotting. We found 1) ET-1 increased RhoA activity (membrane binding RhoA) in a concentration-dependent manner; 2) ET(A), but not ET(B), receptor antagonist abolished the effect of ET-1 on RhoA activation; 3) phosphodylinositol-3 kinase inhibitor, but not PKC and tyrosine kinase inhibitors, reduced ET-1-induced RhoA activation; 4) Rho kinase inhibitor Y-27632 (10 microM) inhibited ET-1-induced contraction; and 5) ET-1 increased the level of MLC phosphorylation. Rho kinase inhibitor Y-27632 reduced the effect of ET-1 on MLC phosphorylation. This study demonstrated that RhoA/Rho kinase activation is involved in ET-1-induced contraction in the rabbit basilar artery. Phosphodylinositol-3 kinase and MLC might be the upstream and downstream factors of RhoA activation.

Topics: Animals; Antihypertensive Agents; Basilar Artery; Endothelin Receptor Antagonists; Endothelin-1; Enzyme Activation; Enzyme Inhibitors; Intracellular Signaling Peptides and Proteins; Male; Oligopeptides; Phosphoinositide-3 Kinase Inhibitors; Piperidines; Protein Kinase C; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Rabbits; Receptor, Endothelin A; Receptor, Endothelin B; rho-Associated Kinases; rhoA GTP-Binding Protein; Vasoconstriction; Vasospasm, Intracranial

We investigated the effects of a platelet-activating factor (PAF) antagonist, E5880 (1-ethyl-2-[N-(2-methoxy)benzoyl-N-[(2)-2-methoxy-3-(4-octadecycarbamoylox)piperidinocarbonyloxy-propyloxy]carbonyl]aminomethyl-pyridiniumchloride), on subarachnoid hemorrhage-induced prolongation of cerebral circulation time and decrease in the basilar artery diameter in a canine double-hemorrhage model. Animals were assigned to three groups, control (saline), E5880 1.2 mg/kg and E5880 2.4 mg/kg. For measurement of cerebral circulation time, regions of interest were chosen at the basilar artery and the straight sinus in order to obtain time-density curves. Cerebral circulation time was defined as the difference between the arterial and venous peaks. Cerebral circulation time and basilar artery diameter were assessed by intra-arterial digital subtraction angiography (IA-DSA) on Days 0, 2 and 7. The prolongation of cerebral circulation time following subarachnoid hemorrhage was significantly inhibited by intravenous administration of 2.4 mg/kg of E5880. Basilar artery constriction was also reduced by E5880. Thus, E5880 had preventive effects on the prolongation of cerebral circulation time and the vasoconstriction of basilar artery in this model. These results suggest that E5880 may have a preventive effect on neurological symptoms aggravated by cerebrovascular lesions following subarachnoid hemorrhage.

Topics: Animals; Basilar Artery; Cerebrovascular Circulation; Disease Models, Animal; Dogs; Female; Male; Piperidines; Platelet Activating Factor; Pyridinium Compounds; Subarachnoid Hemorrhage; Time Factors; Vasoconstriction; Vasospasm, Intracranial

Endothelin-1 (ET-1), a potent vascular smooth muscle constrictor, is one of the possible spasmogens in cerebral vasospasm. However, the role of ET-1 in non-muscle compaction (another aspect of the pathogenesis of cerebral vasospasm) has not been reported. This study was undertaken to demonstrate the effect of ET-1, as well as erythrocyte lysate and bloody cerebrospinal fluid (CSF), on fibroblast populated collagen lattice (FPCL) compaction. Human dermal fibroblasts were used to form FPCL. The concentration-dependent effect of ET-1 was examined in the absence and presence of an ETA receptor antagonist (BQ-485), or an ETB receptor antagonist (BQ-788), or both. FPCL compaction was determined by measuring reduction of areas over five days following treatment. To compare the effect of ET-1 on lattice compaction, erythrocyte lysate and bloody CSF obtained from a cerebral vasospasm patient were also tested. We found that ET-1 increased FPCL compaction in a concentration-dependent (but not time-dependent) manner. Erythrocyte lysate produced the strongest compaction, however, without time-dependence. Bloody CSF promoted FPCL compaction in a time-dependent fashion. Compaction induced by ET-1 was inhibited by BQ-485 but not by BQ-788. We concluded that ET-1 promotes FPCL compaction by activation of ETA receptors. Other components in bloody CSF or erythrocytes may also contribute to FPCL compaction.

Topics: Azepines; Cells, Cultured; Cerebrospinal Fluid; Collagen; Endothelin Receptor Antagonists; Endothelin-1; Erythrocytes; Extracellular Matrix; Fibroblasts; Humans; Oligopeptides; Piperidines; Receptor, Endothelin A; Receptor, Endothelin B; Vasospasm, Intracranial