Prolactin pulsatility in polycystic ovarian disease

Secretion patterns of LH and prolactin were studied in 5 nonobese (group A) and 7 obese (group B) women with polycystic ovaries (PCO) by taking blood samples at 15-min intervals for 6 h. Serum LH level showed a distinct pulsatility in all patients. There was no significant difference in the mean pulse rate of LH between group A (6.2 +/- 0.45, mean +/- SE) and group B (5.8 +/- 0.24). A pulsatile secretion pattern in prolactin was also found in 11 of the 12 PCO patients studied, the pulse rate being 3.2 +/- 1.0 in group A and 3.9 +/- 0.45 in group B. 79% of prolactin pulses coincided with those of LH but their amplitude was significantly lower than that of LH. In the total group of PCO patients a positive correlation was found between the serum concentrations of prolactin and free estradiol (r = 0.85), and prolactin and estrone (r = 0.78) indicating that estrogens participate in the regulation of prolactin secretion in polycystic ovarian disease. Four patients showed a steep decrease in the plasma prolactin level at the beginning of the study period suggesting a sensitive stress response.