ACTH, BETA-ENDORPHIN, SUBSTANCE-P, AND CORTICOTROPIN-RELEASING HORMONE IN PLASMA AND FOLLICULAR-FLUID IN HORMONALLY STIMULATED MENSTRUAL CYCLES FOR IN-VITRO FERTILIZATION IN THE HUMAN

Changes in plasma concentrations of ACTH, beta-endorphin (beta-EP) and cortisol have been found to be associated during the human menstrual cycle. Changes in hypothalamic levels of gonadotrophin releasing hormo ne (GnRH), beta-EP and substance P (SP) have also been associated with the oestrous cycle in the rat. Therefore, an attempt was made to meas ure the activity of the corticotrophic asis and SP by measuring blood and follicular fluid concentrations of ACTH, beta-EP, SP and corticotr ophin releasing hormone (CRH) during the hormonal ovarian stimulation phase for in-vitro fertilization (IVF), in a series of 19 patients. At the plasma level, there was no significant change over treatment days in ACTH (P = 0.1550), beta-EP (P = 0.1137), or SP concentrations (P = 0.5625). CRH was not detectable over treatment days. In addition, the re was no significant change in neuropeptide over treatment days betwe en those women who became pregnant and those who did not (P = 0.17 for all). In the follicular fluid, ACTH was not detectable, beta-EP conce ntration was three times higher than in the plasma, CRH was detectable , and SP concentration was similar to that of plasma. There was no app arent correlation, however, between beta-EP or SP concentrations in th e plasma and follicular fluid from a given patient. In conclusion, the absence of changes in the activity of the corticotrophic axis during the hormonal ovarian stimulation suggests that there was no major stre ss component associated with the stimulation phase of IVF or the occur rence of a pregnancy.