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 prostaglandins (PGs) in the estrogenized rat uterus. Results indicate that epidermal growth factor (EGF) enhances the synthesis of prostaglandins in estrogenized rat uteri and induces the augmentation of nitric oxide (NO) production in this tissue by stimulating iNOS. While the effect of EGF is abolished by L-NMMA, an NO antagonist, the NS-398, a cyclooxygenase-II (COX-II) inhibitor, prevents the augmentation of prostanoids induced by EGF. These results suggest that there is an interaction among EGF, NO and PGs and that in this interrelationship are involved COX-II and iNOS. This mechanism might be important during implantation and labor.