Neuroendocrine events in postmenopausal women: Changes in hypothalamic-pituitary-adrenal and gonadal axis in basal conditions and during hot flushes

The present study refers to the changes of pituitary-adrenal (P-A) and pituitary-gonadal (P-G) axis secretions during hot flushes in a group of menopausal women. ACTH, beta-endorphin (B-EP), beta-lipotropin (B-LPH), cortisol, LH, and FSH plasma levels were measured by radioimmunoassay. B-EP and B-LPH were previously extracted and gel-filtered on Sephadex G-75 columns. Plasma ACTH and cortisol levels did not show any significant differences between postmenopausal and fertile subjects while, B-EP and B-LPH levels in postmenopausal women resulted significantly lower than in the group of fertile women and LH and FSH significantly higher. At the occurrence of hot flushes all hormones measured showed a rapid and significant rise, lasting over 15 minutes; the increase observed in the rise of the hormones of the P-A-axis was higher than that of P-G-axis (P 0.01). These results indicate that plasma B-EP and B-LPH levels undergo a menopausal related decrease while not ACTH, beside the common precursor, and that relevant neuroendocrine events are associated with menopausal hot flushes.