[Role of endogenous opioid peptides in the regulation of pituitary secretions].
Identification of modulatory properties of morphine on certain hormonal secretions and that of opiate-receptor specific endogenous ligands has stimulated research in many fields, including role of opioid peptides in hypophysial secretion regulation. Availability of long-acting agonists and of antagonists of opioid peptides has provided data on their pharmacologic effects and possible role in hormonal physiology. The aim of the present report is to provide an update review of the influence of opioid peptides in hypophysial secretion regulation, while accepting that multiplicity of peptides and receptors does not allow formal conclusions to be drawn. At pharmacologic doses, opioid agonists stimulate prolactin and growth hormone secretion whereas that of LH and ACTH is inhibited. Secretion of TSH is little modified and that of ADH is stimulus-related. The opioid peptides are involved physiologically in the multifactorial regulation of gonadotropin secretion, other hypophysial secretions being mainly unaffected. Finally, "hypothalamic" amenorrhea appears to be the only pathologic model for which opioid peptides can be implicated. Finer analysis of physiologic role of endogenous opioid systems and their possible pathologic effects requires availability of selective agonists and notably antagonists.
D000818:Animals; D004723:Endorphins / Q000502:physiology*; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D016308:Enkephalin, Leucine-2-Alanine; D006065:Gonadotropins, Pituitary / Q000378:metabolism; D006801:Humans; D010902:Pituitary Gland / Q000187:drug effects; D010907:Pituitary Hormones / Q000378:metabolism*
D004723:Endorphins; D006065:Gonadotropins, Pituitary; D010907:Pituitary Hormones; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine
Rôle des peptides opioïdes endogènes dans la régulation des sécrétions hypophysaires.