title: Binding of steroids to blastokinin.
abstract: The authors studied the binding of steroids with Blastokinin (BKN). They confirm that progesterone is the steroid that has a greater affinity for BKN than estradiol or testosterone; the latter is hardly bound to the protein at all. They also show that the presence of estradiol interferes with the formation phase of the BKN-progesterone complex, while testosterone does not. When the BKN-progesterone complex is already formed, a release of the progesterone occurs only when there is a double concentration of estradiol. The biological importance of this phenomenon is briefly discussed.
mesh_terms: D000818:Animals; D001665:Binding Sites; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D007705:Kinins / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism*; D011485:Protein Binding; D011817:Rabbits; D013739:Testosterone / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism
chemical_list: D007705:Kinins; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol