Intravenous self-injection of methcathinone in the baboon.
Methcathinone is a phenylisopropylamine that has been produced by clandestine laboratories and identified in illicit drug traffic. The present study evaluated the intravenous self-administration of methcathinone in three baboons using a cocaine substitution procedure. Intravenous self-injections were available 24 h/day according to a fixed-ratio (FR) schedule with a 3-h timeout following each injection. Doses of racemic methcathinone HCl (0.01-1.0 mg/kg/injection) and its vehicle were substituted for cocaine for 15 or more days. A concurrent FR schedule of food pellet delivery allowed evaluation of any changes in food intake. Self-injection of methcathinone was dose dependent. The lower doses of methcathinone, 0.01 and 0.032, maintained low and intermediate rates of self-injection, respectively, while the higher doses, 0.1, 0.32, and 1.0, maintained rates above vehicle control and comparable to those maintained by cocaine. Acute administration of 3.2 mg/kg to two baboons produced signs of psychomotor stimulant toxicity. Systematic changes in food intake were not observed. The present data indicate that methcathinone functions as a positive reinforcer in baboons and suggests that methcathinone may have abuse potential.
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21224.
B J
BJ
Kaminski
R R
RR
Griffiths
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003042:Cocaine / Q000008:administration & dosage / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D013287:Illicit Drugs; D007275:Injections, Intravenous; D008297:Male; D010215:Papio; D011427:Propiophenones / Q000008:administration & dosage* / Q000633:toxicity; D012054:Reinforcement, Psychology; D012646:Self Administration; D019966:Substance-Related Disorders / Q000209:etiology
D013287:Illicit Drugs; D011427:Propiophenones; C047806:monomethylpropion; D003042:Cocaine