Acute effects of bromocriptine on gonadotropin secretion in polycystic ovary syndrome

Thirty-two women presenting with polycystic ovary syndrome (PCO) were studied on 3 consecutive days. On day 1, plasma androstenedione, testosterone, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEA-S), 17-hydroxyprogesterone (17-OHP), estrone (E1), estradiol, serum prolactin (PRL), and PRL response to thyrotropin-releasing hormone were determined. On day 2 the patients were given two placebos at 1-hour intervals; then serum PRL, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) and the LH and FSH responses to LH-releasing hormone (LH-RH) were determined. On day 3 the patients were given two 2.5-mg tablets of bromocriptine (BRCR) at 12-hour intervals; then serum PRL, LH, and FSH and the LH and FSH responses to LH-RH were again determined. After BRCR, mean values of basal serum PRL (P less than 0.001), LH (P less than 0.05), and FSH (P less than 0.001) and the FSH response to LH-RH (P less than 0.01) fell with respect to the values determined on day 2. Our group of patients was heterogeneous regarding the effects of BRCR upon the LH response to LH-RH. Of 32 women undergoing the trial, 17 did not respond to BRCR (change of the LH response to LH-RH less than 33% with respect to day 2). They were called "nonresponders." Among the 15 who responded to BRCR, 10 decreased their LH response greater than or equal to 33% ("decreasers") and 5 increased their LH response greater than or equal to 33% ("increasers"). Decreasers had mean values of serum PRL, plasma E1, DHEA-S, and 17-OHP higher than nonresponders (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)