Effects of ovarian surgery on the dopaminergic and opioidergic control of gonadotropin and prolactin secretion in women with polycystic ovarian disease

Abstract

Ovarian surgery has been demonstrated as an effective means to establish regular menstrual cycles and resumption of ovulation in patients with polycystic ovarian disease (PCO). We questioned whether such reinstitution of menstrual cyclicity may be associated with changes in the opioidergic and dopaminergic activity known to be aberrant in these women. Opioidergic and dopaminergic tone was therefore assessed in patients with PCO before and after ovarian laser vaporization (n = 4) or classical ovarian wedge resection (n = 4). Blood samples for the determination of luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin were frequently obtained following opioidergic and/or dopaminergic antagonism affected by naloxone (4 mg i.v.) or metoclopramide (10 mg i.v.). In response to either surgical approach, circulating LH levels decreased (p < 0.01), while FSH concentrations remained unaltered. Further, LH and FSH concentrations did not noticeably change following challenges with naloxone or metoclopramide: this applied to conditions before and after ovarian surgery. Prolactin release in response to metoclopramide was markedly (p < 0.01) higher following ovarian surgery than before. Thus, both ovarian laser surgery and classical wedge resection can effectively restore normal menstrual cyclicity in PCO patients, although they failed to alter opioidergic and dopaminergic activity. Dopaminergic inhibition of prolactin secretion was further enhanced after ovarian surgery. These observations suggest that different modes of ovarian surgery are effective in influencing central gonadal control, but that the central opioidergic and dopaminergic control of gonadotropin and prolactin secretion remains unaffected by ovarian surgery in PCO women, even when menstrual cyclicity is resumed.