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Dopaminergic regulation of gonadotropin levels and pulsatility in normal women

1987; Elsevier BV; Volume: 47; Issue: 3 Linguagem: Inglês

10.1016/s0015-0282(16)59043-8

1556-5653

Anders Nyboe Andersen, Claus Hagen, P. Lange, Søren Boesgaard, Henning Djursing, Ebbe Eldrup, Snezana Micic,

Hypothalamic control of reproductive hormones

This study was done to define the concentration of dopamine (DA) that inhibits gonadotropin secretion and to study the effect of DA D-2 receptor blockade during the infusions. Normal women received 5-hour infusions of either glucose (n = 14) or DA at rates of 0.04 (n = 6), 0.4 (n = 6), and 4.0 μg/kg · minute (n = 9). After 3 hours, metoclopramide (MTC) was administered. Mean serum luteinizing hormone (LH) concentration declined during 0.4 (P < 0.01) and 4.0 μg/kg · minute (P < 0.05) infusion doses of DA. This effect of DA was not consistently (P > 0.05) antagonized by MTC. Six women received DA (4.0 μg/kg · minute) or glucose for 18 hours. After 17 hours, MTC was given. Blood samples were collected every 10 minutes during the last 8 hours. No significant effect on LH pulse frequency and pulse amplitude was observed (P > 0.05). A marked (P < 0.01) rise in LH occurred after MTC administration. The authors conclude that (1) physiologic doses of DA may inhibit LH secretion with only little, if any, effect on the pulsatile release; and (2) low-affinity DA receptors responsive to DA D-2 antagonists may regulate LH secretion.