title: Characteristics of the early effect of prolactin on lactose biosynthesis in mouse mammary gland explants.
abstract: These studies were carried out to characterize the early effect of prolactin (PRL) on lactose biosynthesis in cultured mammary gland explants derived from 12- to 14-day pregnant mice. The rate of lactose biosynthesis was assessed by the rate of radiolabeled glucose incorporation into lactose. For the rapid isolation of lactose, a new method which involves the use of thin-layer chromatography on cellulose-impregnated plastic sheets was employed. The onset of the PRL stimulation of [3H]glucose incorporation into lactose occurred 6-8 hr after exposing the explants to PRL. The response to PRL was essentially all or none with maximum responses occurring with PRL concentrations above 25 ng/ml. The lowest stimulatory concentration of PRL was 10 ng/ml. The action of PRL on lactose biosynthesis requires both ongoing RNA and protein synthesis since puromycin, cyclohexamide, and actinomycin D abolished the PRL effect.
authors: Department of Physiology, Wayne State University, School of Medicine, Detroit, Michigan 48201.
authors: C A
authors: CA
authors: Oppat
authors: J A
authors: JA
authors: Rillema
mesh_terms: D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D005260:Female; D005947:Glucose / Q000378:metabolism; D007700:Kinetics; D007785:Lactose / Q000096:biosynthesis*; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D011247:Pregnancy; D011388:Prolactin / Q000494:pharmacology*; D014176:Protein Biosynthesis; D011691:Puromycin / Q000494:pharmacology; D012313:RNA / Q000096:biosynthesis
chemical_list: D003609:Dactinomycin; D011691:Puromycin; D012313:RNA; D011388:Prolactin; D003513:Cycloheximide; D005947:Glucose; D007785:Lactose