Effects of cocaine and related drugs in nonhuman primates. III. Self-administration by squirrel monkeys

J Pharmacol Exp Ther. 1989 Oct;251(1):150-5.

Abstract

The self-administration of cocaine was compared with that of bupropion, 1-(2-[bis(4-fluorophenyl)methoxy]ethyl]-4-(3-phenylpropyl)piperazine, mazindol, methylphenidate and nomifensine, drugs that displace [3H]cocaine from its binding sites and have monoamine uptake inhibiting effects in common with those of cocaine. Squirrel monkeys responded under a second-order fixed-interval schedule of consequent i.v. drug injection, and dose-effect curves were established by determining stable rates of responding maintained by saline and a range of doses of each drug. Cocaine (0.01-0.56 mg/kg/injection), bupropion (0.1-3.0 mg/kg/injection), 1-(2-[bis(4-fluorophenyl)methoxy]ethyl)-4-(3- phenylpropyl)piperazine-(0.03-1.0 mg/kg/injection), methylphenidate (0.01-0.3 mg/kg/injection) and nomifensine (0.01-0.3 mg/kg) maintained comparable rates and patterns of responding in all subjects, whereas mazindol (0.03-0.3 mg/kg) maintained self-administration behavior in only half the monkeys studied. The present results in conjunction with those of previous studies in squirrel monkeys reveal a close correspondence between the relative potencies of cocaine and related drugs for maintaining i.v. self-administration and for increasing rates of schedule-controlled responding, suggesting that the reinforcing and psychomotor-stimulant effects of the drugs are mediated similarly. The potency relations observed in the present study also agree generally with those observed for displacement of specifically bound [3H]cocaine in monkey caudate-putamen suggesting that the reinforcing effects of cocaine involve its actions at specific recognition sites in brain.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Bupropion
  • Cocaine / pharmacology*
  • Dopamine / metabolism
  • Male
  • Mazindol / pharmacology
  • Methylphenidate / pharmacology
  • Neurotransmitter Uptake Inhibitors / pharmacology*
  • Nomifensine / pharmacology
  • Piperazines / pharmacology
  • Propiophenones / pharmacology
  • Saimiri
  • Self Administration

Substances

  • Neurotransmitter Uptake Inhibitors
  • Piperazines
  • Propiophenones
  • Bupropion
  • Nomifensine
  • Methylphenidate
  • vanoxerine
  • Mazindol
  • Cocaine
  • Dopamine