Possible contribution of follicular interleukin-1beta to nitric oxide generation in human pre-ovulatory follicles

The aim of this study was to investigate the relationships betweenfollicular nitric oxide (NO) metabolite concentrations and several relatedvariables, with special reference to follicular interleukin- 1beta(IL-1beta). The follicular fluid from the leading and secondary follicleswas collected individually from 20 women undergoing in-vitro fertilization(IVF) treatment, and the concentrations of nitrite (NO2-) and nitrate(NO3-) were determined fluorometrically using 2,3- diaminonaphthalene. Bothfollicular nitrite (r = 0.42, P < 0.01) and nitrate (r = 0.49, P <0.001) were found to be significantly correlated with follicular IL-1betaconcentrations. There were also significant positive correlations betweenfollicular nitrate and the number of oocytes retrieved (P < 0.01) andserum oestradiol concentration on the day of human chorionic gonadotrophin(HCG) administration (P < 0.05). When follicular cells were incubated invitro with 10 ng/ml of IL-1beta for 24 h, nitrate generation wassignificantly (P < 0.01) elevated compared with the control. Inconclusion, our study demonstrates that follicular IL-1beta and the numberof developing follicles are significant variables that affect follicular NOconcentrations, and points to the possible contribution of IL-1beta to NOgeneration in human preovulatory follicles.