The effect of epidermal growth factor on prostaglandin synthesis of oestrogenized rat uterus is mediated by nitric oxide

We examined the possible relationship between cytokines, nitric oxide and p rostaglandins (PGs) in the estrogenized rat uterus. Results indicate that e pidermal growth factor (EGF) enhances the synthesis of prostaglandins in es trogenized rat uteri and induces the augmentation of nitric oxide (NO) prod uction in this tissue by stimulating iNOS. While the effect of EGF is aboli shed by L-NMMA, an NO antagonist, the NS-398, a cyclooxygenase-ll (COX-II) inhibitor, prevents the augmentation of prostanoids induced by EGF. These r esults suggest that there is an interaction among EGF, NO and PGs and that in this interrelationship are involved COX-II and iNOS. This mechanism migh t be important during implantation and labor. (C) 1999 Harcourt Publishers Ltd.