title: [Short-term effect of prolactin on its receptor].
abstract: It is known that prolactin (PRL) when injected chronically is able to increase the level of its own receptors. We have shown here that, after a single IV injection of PRL to lactating rabbits, total prolactin-receptor levels (measured after in vitro desaturation of injected prolactin by a MgCl2 treatment of the membranes) decreased from 41.6 to 18.4 p. 100 (specific binding) in 6 hrs. The same results were obtained in organ-culture of the rabbit mammary gland in the presence of prolactin; in addition, the down-regulation of prolactin receptors could be counteracted by lysosomotropic agents (chloroquine NH4Cl) in vitro. These results showed that prolactin could, at short term, induce a down regulation of its receptors, and that this effect might be related to an endocytosis of hormone-receptor complex and lysosome degradation.
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D002738:Chloroquine / Q000494:pharmacology; D005260:Female; D007774:Lactation; D011247:Pregnancy; D011388:Prolactin / Q000494:pharmacology*; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000187:drug effects*; D011981:Receptors, Prolactin; D013997:Time Factors
chemical_list: D011956:Receptors, Cell Surface; D011981:Receptors, Prolactin; D000643:Ammonium Chloride; D002738:Chloroquine; D011388:Prolactin
vernacular_title: Effet à court terme de la prolactine sur son récepteur.