Mu- and kappa-opiate receptor control of prolactin secretion in rats: ontogeny and interaction with serotonin.


Journal Article

The present study explores developmental changes in mu- and kappa-opiate receptor control of PRL secretion. The ontogeny of mu- and kappa-receptor function was determined by assessing the PRL response to the mu-agonist sufentanil (SUF) and the kappa-agonist U50488 in 5-, 10-, 15-, 20-, and 60-day-old rats. Both mu- and kappa-agonists stimulated PRL secretion at all ages. The selectivity of the mu- and kappa-agonists was confirmed by selective blockade with their respective antagonists (beta-funaltrexamine and nor-binaltorphimine). Serotonin mediation of opiate-induced changes in PRL secretion was explored across ontogeny by testing cyproheptadine (CYPRO) blockade of agonist responses in 5-, 10-, 20-, and 60-day-old rats. CYPRO attenuated the PRL response to the mu-agonist SUF in 20- and 60-day-old rats, but not in the 5- or 10-day-old pups. CYPRO did not block the kappa-agonist U50488 at any age. Similarly, pretreatment with parachlorophenylalaine lowered the PRL response to SUF in 60-day-old rats, but not in 10-day-old rats. These results support previous reports of a serotonin-mediated mu control of PRL secretion that develops by day 20 and a kappa control of PRL secretion that is independent of serotonin at all ages. These findings also suggest that a previously reported serotonin-independent mu-receptor-mediated control of PRL secretion can be stimulated early in ontogeny.

Full Text

Duke Authors

Cited Authors

  • Blackford, SP; Little, PJ; Kuhn, CM

Published Date

  • December 1992

Published In

Volume / Issue

  • 131 / 6

Start / End Page

  • 2891 - 2897

PubMed ID

  • 1332851

Pubmed Central ID

  • 1332851

International Standard Serial Number (ISSN)

  • 0013-7227

Digital Object Identifier (DOI)

  • 10.1210/endo.131.6.1332851


  • eng

Conference Location

  • United States