Effects of prostacyclin and 6-keto PGF1α on electrically induced convulsions in mice

Intracerebroventricular administration of prostacyclin (PGI2) was shown to block the incidence of tonic convulsions in mice. Prostacyclin was administered intracerebroventricularly (i.c.v.) to conscious mice prior to a transcorneal maximal electroshock (MES) or supra-maximal electroshock (SMES) as previously described (1). PGI2 i.c.v. blocked the tonic hindlimb extension (THE) and protected the animals from death induced by MES with an ED50 of 6.27 (2.53–11.10) μg/mouse i.c.v. The i.c.v. administration of its degradation product 6-keto PGF1α had no effect on the incidence of tonic convulsions but did reduce the duration of THE significantly. When PGI2 was administered intraperitoneally in doses as high as 2 mg/kg it did not block the THE. However, the duration of the THE as well as mortality were reduced by doses ranging from 0.25–2.0 mg/kg i.p. Prostacyclin caused a significant dose-related (p<.001) decrease in the duration of the THE with SMES in doses of 20–140 μg/mouse i.c.v. No concomitant decrease in the incidence of tonic convulsions was found against SMES.