INTRAVENOUS SELF-ADMINISTRATION OF DOPAMINE RECEPTOR AGONISTS BY RHESUS-MONKEYS

Abstract

Pharmacological studies have provided important information relevant to the behavioral role of CNS dopamine (DA) and the existence of multiple DA receptors in the CNS. The i.v. self-administration of several compounds that are direct DA receptor agonists was evaluated in rhesus monkeys. Apomorphine piribedil, propylbutyldopamine and bromocriptine were self-administered by at least half of the animals tested; SKF 38393 failed to maintain self-administration. Each of the compounds that was self-administered is an agonist at the DA2 receptor that has been demonstrated in the periphery; SKF 38383 is principally a DA1 agonist. A DA receptor that is similar to the DA2 receptor is apparently involved in this behavioral effect. The hypothesis that CNS DA is involved in the reinforcing properties of psychomotor stimulants was supported.