TRANSCORTIN: A CORTICOSTEROID-BINDING PROTEIN OF PLASMA. III. THE EFFECTS OF VARIOUS STEROIDS *†

Abstract

The administra-tion of adequate amounts of estrogens produces increased concentrations of transcortin within 3 to 7 days, followed by a rise in the levels of the 17-hydroxycorticosteroids (17-OHCS). These levels declined to normal within 7 to 10 days after cessation of estrogen treatment. The increased concentration of transcortin can be induced by estrogens in the absence of the adrenal gland. Testosterone propionate, 17[alpha]-methyl-19-nortestosterone and 2[alpha]-methyldihydrotestosterone propionate failed to change the transcortin or 17-OHCS concentrations. The increased transcortin concentrations in pregnant women had changed little within 5 days postpartum and were normal 6 weeks after delivery. ACTH, surgical stress, and intravenous cortisol decreased the transcortin binding of C14-cortisol and transcortin capacity. Lymph fluids contain transcortin and 17-OHCS in slightly lower concentrations than those seen in plasma.