Androstenedione and estrone dynamics in hypothyroid women.
To examine the effects of hypothyroidism on androstenedione (A) and estrone (E1) metabolism, we infused eight women with [3H]androstenedione and [14C]estrone when they were hypothyroid and again when they were euthyroid after levo-T4 administration. MCRs and conversion ratios were measured using concentrations of radioactivity in the blood pools of A and E1. Peripheral aromatization was measured from the concentrations of radioactivity in the E1 glucuronide pool in the urine. After the women were euthyroid, the MCR of A had increased in seven of eight, the MCR of E1 increased in all eight, and peripheral aromatization had decreased in seven of eight. These findings indicate that hypothyroidism results in a decrease in the MCRs of A and E1 and, in most subjects, an increase in peripheral aromatization of A to E1.
Longcope
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Department of Obstetrics and Gynecology, University of Massachusetts Medical School, Worcester 01655.
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Braverman
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Emerson
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D000328:Adult; D000735:Androstenedione / Q000493:pharmacokinetics*; D004970:Estrone / Q000493:pharmacokinetics*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000188:drug therapy; D007262:Infusions, Intravenous; D007700:Kinetics; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000627:therapeutic use; D014284:Triiodothyronine / Q000097:blood
D014284:Triiodothyronine; D004970:Estrone; D000735:Androstenedione; D013972:Thyrotropin; D013974:Thyroxine