title: A receptor site for prolactin in lactating mouse mammary tissues.
abstract: Prolactin iodinated by lactoperoxidase method showed immunologically, electrophoretically and biolo9gically similar properties to native prolactin and possessed enough specific radioactivity for receptor studies. 1251-prolactin was incubated with mouse mammary tissues at 8 days of lactation. Both binding and release of 1251-prolactin depended on incubation time and temperature and were maximal at 37 degrees C. Michaelis constant was estimated to be 1.4 X 10(-9) M from Lineweaver-Burk plot and to be 1.2 X 10(-9) M from id-value of the dose-response curve for displacement with native prolactin. Total number of binding sites for prolactin was 1.38 X 10(-15) mole per mg weight of tissue. Ovine prolactin, human growth hormone and human placental lactogen complete with 1251-prolactin and dose-response curves for these three hormones were all parallel. These results suggest the existence of a specific receptor site with high affinity for prolactin in lactating mouse mammary glands.
mesh_terms: D000818:Animals; D001665:Binding Sites; D005260:Female; D007774:Lactation; D008321:Mammary Glands, Animal / Q000378:metabolism*; D051379:Mice; D011247:Pregnancy; D011388:Prolactin / Q000378:metabolism*; D011956:Receptors, Cell Surface
chemical_list: D011956:Receptors, Cell Surface; D011388:Prolactin