Effects of desglycinamide9, (Arg8) vasopressin and vasopressin antiserum on the acquisition of intravenous cocaine self-administration in the rat.
The effect of the vasopressin neuropeptide desglycinamide9, (Arg8) vasopressin (DGAVP) on the acquisition of intravenous cocaine self-administration was studied. Rats were tested under conditions of reduced body weight in a continuous reinforcement operant procedure, during five daily 3 h sessions. Under these conditions, the rate of self-administration obtained with 0.125 and 0.25, but not 0.063 mg.ml-1 cocaine, exceeded the rate obtained with saline. Daily pretreatment with DGAVP (5 micrograms/rat, s.c.) decreased self-administration of 0.125 and 0.25 mg.ml-1 cocaine to the level obtained with saline, but had no effect on self-administration of 0.063 mg.ml-1 cocaine and saline. Using a similar procedure, it was shown that daily intracerebroventricular pretreatment with vasopressin antiserum significantly increased self-administration of 0.125 mg.ml-1 cocaine, without affecting self-administration of 0.063 and 0.25 mg.ml-1 cocaine and saline. The results support previous findings obtained with vasopressin neuropeptides in drug self-administration studies and suggest that DGAVP decreases the acquisition of cocaine self-administration by attenuating the reinforcing effects of cocaine and that endogenous vasopressin may be involved in the acquisition of cocaine self-administration.
de Vry
J
J
Rudolf Magnus Institute for Pharmacology, Medical Faculty, University of Utrecht, The Netherlands.
Donselaar
I
I
van Ree
J M
JM
D000818:Animals; D000937:Antigen-Antibody Reactions; D001127:Arginine Vasopressin / Q000031:analogs & derivatives* / Q000494:pharmacology; D003042:Cocaine / Q000008:administration & dosage*; D007158:Immunologic Techniques; D008297:Male; D051381:Rats; D012646:Self Administration; D019966:Substance-Related Disorders / Q000503:physiopathology; D014667:Vasopressins / Q000037:antagonists & inhibitors*
D014667:Vasopressins; D001127:Arginine Vasopressin; C015119:argipressin, des-GlyNH2(9)-; D003042:Cocaine