Effects of intracerebroventricular administration of PGE1, E2 and F2alpha on electrically induced convulsions in mice.

Intracerebroventricular administration of prostaglandins E1 or E2 was shown to block, while PGF2alpha increased the incidence of tonic convulsion due to electroshock in mice. The Prostaglandins were administered intracerebroventicularly (i.c.v.) to conscious mice by a modification of Haley and McCormick's method (1) prior to a transcorneal maximal electroshock (MES) or a transcorneal supra-maximal electroshock (SMES). PGE1 and PGE2 i.c.v. blocked the tonic hindlimb extension (THE) and protected the animals from death induced by MES with ED50's for PGE1 and PGE2 for inhibition of the THE of 6.6 (4.3--12.0) microgram/mouse i.c.v. and 13.3 (8.9--22.4) microgram/mouse i.c.v. respectively. When PGE2 was administered intraperitoneally (i.p.) in doses as high as 4.0 mg/kg it did not block the THE. However, the duration of the THE as well as the mortality were reduced by doses of 0.5--4.0 mg/kg PGE2 i.p.. Both PGE1 and PGE2 were shown to cause a dose related significant (p less than .001) decrease in the duration of the THE with SMES in doses of 1--10 microgram/mouse i.c.v. for PGE1 and 2--40 microgram/mouse i.c.v. for PGE2. PGF2alpha, administered i.c.v. prior to a transcorneal electroshock equivalent to a current at the ED1 level, increased the incidence of the THE as well as the mortality in doses of 20--50 microgram/mouse.