D-1 dopamine agonist administration reduces the threshold for convulsions produced by pilocarpine.
Focal, limbic seizures were produced by systemically administered pilocarpine (200 mg/kg, i.p.); as previously described this dose produces limbic stereotypies but neither convulsions nor seizure-related brain damage. The pretreatment, 5 minutes prior pilocarpine, with the D-1 agonist SKF 38393 (-ED50 = 1 mg/kg; i.p.) induced convulsions similar to those produced by a higher, convulsant dose of pilocarpine. On the other hand, the pretreatment with the D-2 agonist LY 171555 failed to induce convulsions. The D-1 receptor antagonist SCH 23390 prevented the convulsions induced by SKF 38393 plus pilocarpine (200 mg/kg). This study indicates that D-1, but not D-2, receptor stimulation converts subconvulsant doses of pilocarpine into convulsant ones.
Barone
P
P
Palma
V
V
Parashos
S A
SA
Marin
C
C
Chase
T N
TN
Campanella
G
G
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003292:Convulsants / Q000494:pharmacology*; D015259:Dopamine Agents / Q000494:pharmacology*; D004357:Drug Synergism; D004873:Ergolines / Q000494:pharmacology; D008297:Male; D010862:Pilocarpine / Q000494:pharmacology / Q000633:toxicity*; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000145:classification / Q000187:drug effects; D012640:Seizures / Q000139:chemically induced*
D001552:Benzazepines; D003292:Convulsants; D015259:Dopamine Agents; D004873:Ergolines; D011954:Receptors, Dopamine; D010862:Pilocarpine; D019257:Quinpirole; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine