Comparative profiles of sodium valproate and ethosuximide on electro-behavioural correlates in gamma-hydroxybutyrate and pentylenetetrazol induced absence seizures in rats.
Sodium valproate (VPA) and ethosuximide (ESM) were compared on behavioural and EEG changes in gamma-hydroxybutyrate (GHB) and pentylenetetrazole (PTZ) rat models of Absence Seizures (AS). Both GHB, 100 mg/kg i.p. and PTZ, 20 mg/kg i.p., produced repetitive episodes of staring and immobility with concomitant 6 to 9 Hz spike and wave discharges (SWDs) in the EEG. The parameters used for drug evaluation were the number and duration of SWDs/hour. Though the number of SWDs/hour produced by GHB and PTZ were not significantly different, the duration of SWDs was significantly longer in GHB treated rats (P < 0.001) VPA and ESM, at 200 mg/kg i.p., reduced SWD number and duration in GHB pretreated rats, whereas ESM, 50 mg/kg i.p., was four times more effective than VPA, 200 mg/kg i.p., in the PTZ model. Phenytoin (PHY) 20 and Carbamazepine (CBZ) 10 mg/kg i.p., worsened AS, a feature which has also been reported clinically. Both rat models of experimental AS can be used to defect potential anti-absence activity in new chemical entities.
Kumaresan
S
S
Department of Pharmacology, St. John's Medical College, Bangalore-560 034.
David
J
J
Joseph
T
T
D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use*; D003292:Convulsants; D004195:Disease Models, Animal; D004569:Electroencephalography / Q000187:drug effects*; D004832:Epilepsy, Absence / Q000139:chemically induced / Q000188:drug therapy*; D005013:Ethosuximide / Q000627:therapeutic use*; D008297:Male; D010433:Pentylenetetrazole; D051381:Rats; D017208:Rats, Wistar; D012978:Sodium Oxybate; D013045:Species Specificity; D014635:Valproic Acid / Q000627:therapeutic use*
D000927:Anticonvulsants; D003292:Convulsants; D005013:Ethosuximide; D014635:Valproic Acid; D012978:Sodium Oxybate; D010433:Pentylenetetrazole