[Effect of anticonvulsants upon experimental limbic seizure status and regional cerebral blood flow in the hippocampus].
Continuous monitoring of regional cerebral blood flow (rCBF) of the hippocampus was made during limbic seizure status in cats by means of a heat clearance method with a calibration method by an electrolytic hydrogen clearance method. A stereotaxic operation was made under Nembutal anesthesia. Local anesthetics were applied to the painful area. Femoral artery and vein were cannulated and served for arterial blood pressure monitoring and drug injection, respectively. Tracheostomy was made and ventilated artificially. A double cannula was inserted to the amygdala and fixed to the skull with a dental cement. Electrodes for heat clearance method, electrolytic hydrogen clearance method and EEG recording were inserted to the dorsal hippocampus. Limbic seizure status was induced by kainic acid microinjection (2 ug) into amygdala via implanted cannula. Baseline rCBF was measured in each cats. Continuous monitoring of rCBF was made before and after intravenous administration of anticonvulsants such as zonisamide (ZNS), valproic acid (VPA), diazepam (DZP), phenobarbital (PB) and phenitoin (PHT). Physiological saline (PHS) was injected for controls. Injection of DZP resulted in strong seizure suppression with decrease of arterial blood pressure and hippocampal rCBF. Intravenous PB demonstrated analogous action with DZP with a mild anticonvulsant effect. Intravenous ZNS or VPA resulted in inhibition of seizure propagation from limbic system to cortex. However, these drugs augmented rCBF of the hippocampus more than 2 hours after administration. PHT and PHS demonstrated no anticonvulsant effect nor rCBF change in the present study.
Tanaka
T
T
Department of Neurosurgery, Asahikawa Medical College, Japan.
Fujita
T
T
Tanaka
S
S
Takano
K
K
Yonemasu
Y
Y
D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D002415:Cats; D003975:Diazepam / Q000494:pharmacology; D004569:Electroencephalography; D006624:Hippocampus / Q000098:blood supply* / Q000187:drug effects; D007555:Isoxazoles / Q000494:pharmacology; D010634:Phenobarbital / Q000494:pharmacology; D010672:Phenytoin / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D013226:Status Epilepticus / Q000503:physiopathology*; D014635:Valproic Acid / Q000494:pharmacology; D000078305:Zonisamide
D000927:Anticonvulsants; D007555:Isoxazoles; D000078305:Zonisamide; D014635:Valproic Acid; D010672:Phenytoin; D003975:Diazepam; D010634:Phenobarbital