3-(3-hydroxyphenyl)-N-n-propylpiperidine (3-PPP) has been reported to be a relatively selective agonist for dopamine (DA) auto-receptors in the striatal and limbic region. We have examined the effect of 3-PPP on rat plasma or serum prolactin levels. 3-PPP produced a non-significant decrease in baseline plasma prolactin levels. It produced a dose-dependent inhibition of the increase in serum prolactin levels produced by gamma-butyrolactone. Both doses of 3-PPP tested completely reversed the increase in serum prolactin levels.produced by reserpine and alpha-methylparatyrosine. These results strongly indicate that 3-PPP directly stimulated DA receptors on pituitary lactotrophes. 3-PPP only weakly inhibited the ability of 3H-spiroperidol to bind to pituitary or striatal membranes, suggesting that it may act at a different DA receptor than classical DA receptor blocking drugs. This DA receptor could have properties in common with the autoreceptors of the mesolimbic and nigrostriatal DA neurons.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)