title: [Role of lysosomes, microtubules and microfilaments in the mechanism of the lactogenic action of prolactin in the rabbit mammary gland].
abstract: The lysosomotropic agents, ammonium chloride and chloroquine, added to the culture medium of pseudopregnant Rabbit mammary gland, did not inhibit the initiation of casein synthesis by prolactin. By contrast, they considerably reduced the down-regulation of prolacting receptors. Converse-y, colchicine totally blocked the lactogenic action of prolactin without altering the down-regulation of the receptor. Cytochalasin B inhibited only partly the lactogenic action of prolactin while it has no effect on the down-regulation of the receptor. These data suggest that the degradation of the prolactin-receptor complex in lysosome is not a compulsory step in the mechanism of prolactin action. The integrity of microtubules but not of microfilaments is required for prolactin to initiate casein synthesis. These elements of the cytoskeleton are not strictly involved in the down-regulation of the receptor.
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D002364:Caseins / Q000096:biosynthesis; D002417:Cattle; D002738:Chloroquine / Q000494:pharmacology; D003078:Colchicine / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D003599:Cytoskeleton / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D007774:Lactation; D008247:Lysosomes / Q000187:drug effects / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000502:physiology*; D008870:Microtubules / Q000502:physiology*; D011247:Pregnancy; D011388:Prolactin / Q000502:physiology*; D011555:Pseudopregnancy / Q000503:physiopathology; D011817:Rabbits
chemical_list: D002364:Caseins; D000643:Ammonium Chloride; D003571:Cytochalasin B; D002738:Chloroquine; D011388:Prolactin; D003078:Colchicine
vernacular_title: Rôle des lysosomes, des microtubules et des microfilaments dans le mécanisme de l'action lactogène de la prolactine sur la glande mammaire de Lapine.