title: A homologous radioimmunoassay for canine prolactin: plasma levels during the reproductive cycle.
abstract: A method is described for the purification of canine prolactin, involving preparative isoelectrofocusing. Canine prolactin has a molecular weight of 23 000 daltons, an isoelectric point of 5.7 and exhibits a high degree of homogeneity in polyacrylamide gels stained by means of a silver method. A specific, homologous radioimmunoassay is described using the Bolton-Hunter method for preparation of the labelled ligand, with a sensitivity of 0.1 ng/tube. Basal plasma prolactin levels of 2-4 ng/ml obtained through the oestrous cycle remained fairly constant but a rise of 9 ng/ml was found at the end of dioestrus in non-pregnant bitches. Level also rose 30 days after mating to reach a peak of about 50 ng/ml near parturition and during early lactation.
mesh_terms: D000818:Animals; D004285:Dogs; D004971:Estrus; D005260:Female; D007525:Isoelectric Focusing; D008970:Molecular Weight; D011247:Pregnancy; D011388:Prolactin / Q000097:blood / Q000302:isolation & purification*; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D011388:Prolactin