Prolactin binding sites on human chorion-decidua tissue.
An effective procedure has been developed and utilized to demonstrate the presence of prolactin receptors on the plasma membranes of human chorion-decidua cells. Particulate fractions from human chorion-decidua sedimenting between 1,500 and 45,000 x g display optimal binding of 215I-labeled ovine prolactin when incubated at a membrane protein concentration of 200 micrograms per assay tube for 2 hours at 22 degrees C. Specific binding was increased by pretreatment of the membrane particles with 5M magnesium chloride to remove endogenous prolactin. These receptors show binding parameters (affinity, 0.92 x 10(9) L/mode; capacity, approximately 80 fmoles/mg) similar to those of lactogenic receptors in the rabbit mammary gland and, the rabbit and rat liver. The presence of prolactin receptors in human chorion-decidua suggests that may play a role in mediating local action(s) of prolactin such as involvement in the decidualization reaction or in maintaining fetal osmoregulation.
D002462:Cell Membrane / Q000032:analysis; D002823:Chorion / Q000032:analysis*; D003656:Decidua / Q000032:analysis*; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008274:Magnesium; D015636:Magnesium Chloride; D011247:Pregnancy; D011956:Receptors, Cell Surface / Q000032:analysis*; D011981:Receptors, Prolactin; D013997:Time Factors
D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D011981:Receptors, Prolactin; D015636:Magnesium Chloride; D008274:Magnesium