Verapamil does not antagonize LSD-induced stimulus control.
Discriminative stimulus control was established in rats (N = 6) with LSD (100 microg/kg) and saline using a 2-lever response choice task and an FR10 schedule of food reinforcement. Subjects were then tested once per week with either pizotyline (BC-105) or verapamil alone or in combinations with LSD. In In agreement with previous reports, pizotyline antagonized LSD and, when tested alone, exhibited modest agonistic effects (18% LSD-appropriate). In contrast, verapamil failed to block LSD at any dose tested. Verapamil alone appeared to have somewhat greater agonistic activity (35% LSD-appropriate) than did pizotyline but neither drug substituted completely for LSD. These data suggest that calcium channel antagonism by pizotyline is not essential to its anti-LSD effects.
D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects; D004193:Discrimination Learning; D005502:Food; D008238:Lysergic Acid Diethylamide / Q000037:antagonists & inhibitors*; D008297:Male; D010918:Pizotyline / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D013876:Thiophenes / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology*
D013876:Thiophenes; D010918:Pizotyline; D008238:Lysergic Acid Diethylamide; D014700:Verapamil