Effects of intracerebral iloprost injections on motor activity and chemically-induced seizures in rats.
The effects of iloprost, a chemically stable analog of prostacyclin, on motor activity, pentylenetetrazol (PTZ)- and strychnine (ST)-induced seizures were studied in rats. Depression on motor activity was observed after a 500 ng/icv dose. Thus, both spontaneous locomotor activity and exploratory behavior were significantly reduced. While iloprost was ineffective against ST-induced seizures, it produced dose-dependent inhibition of PTZ-induced seizures. ED50 (95% confidence limits) value of iloprost for the suppression of clonic convulsions induced by PTZ was 224.96 (100.43-504.00) ng/icv. Anticonvulsive effect of iloprost was significantly potentiated by clonazepam pretreatment. In this case ED50 of iloprost was 39.40 (23.88-65.01) ng/icv. Unilateral iloprost injections into substantia nigra pars reticulata in a relatively lower dose range (0.5-2.0 ng/ic) also dose-dependently inhibited PTZ-induced seizures. In comparison to other prostanoids iloprost seems to have more potent and selective anticonvulsive activity against PTZ-induced seizures without marked motor depressant action in rats. It is further suggested that antiseizure effect of iloprost might be mediated by GABAergic inhibitory mechanisms.
Akarsu
E S
ES
University of Ankara, Faculty of Medicine, Department of Pharmacology, Turkey.
Ayhan
I H
IH
D000818:Animals; D002998:Clonazepam / Q000494:pharmacology; D016285:Iloprost / Q000008:administration & dosage / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D012640:Seizures / Q000139:chemically induced / Q000188:drug therapy*
D002998:Clonazepam; D016285:Iloprost