title: Assessment of mammary lactogenic receptor changes in pregnant rabbits.
abstract: Lactogenic receptor was purified from rabbit mammary tissue and used to generate an antiserum in goats. The purified lactogenic receptor material bound lactogenic hormones specifically and reversibly. Antiserum generated in a goat bound a labeled human growth hormone/receptor complex; this was displaced by nonlabeled solubilized receptor preparations. This was used as a radioimmunoassay and was able to detect 0.037 fmol of lactogenic receptor. The specificity of the radioimmunoassay for lactogenic receptor was supported by three lines of evidence; first, the ligand used in the radioimmunoassay was an iodine 125-labeled human growth hormone/receptor combination; therefore, only membrane protein with structural homology to the protein which bound 125I-labeled human growth hormone competed for binding to the antiserum; second, depletion of radioreceptor binding sites by affinity chromatography with ovine prolactin as the fixed ligand was detected; third, an increase in breast lactogenic receptor during pregnancy was detected by both radioreceptor assay and the radioimmunoassay. We found a progressive increase in lactogenic receptors by radioimmunoassay which corresponded to parallel increases by radioreceptor assay in rabbit mammary tissue during pregnancy.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002846:Chromatography, Affinity; D005260:Female; D006041:Goats / Q000276:immunology; D007457:Iodine Radioisotopes; D008321:Mammary Glands, Animal / Q000032:analysis*; D011247:Pregnancy; D011270:Pregnancy, Animal; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods; D011869:Radioligand Assay; D011956:Receptors, Cell Surface / Q000032:analysis* / Q000276:immunology; D011981:Receptors, Prolactin; D013045:Species Specificity
chemical_list: D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D011981:Receptors, Prolactin