Nitric oxide in the contractile action of bradykinin, oxytocin, and prostaglandin F_2α in the estrogenized rat uterus

摘要

Experiments were performed on uteri from estrogen-primed female rats. Bradykinin (BK) (10~-) significantly augmented biosynthesis of prostaglandin F2 α (PGF2α) and prostaglandin E_2 (PGE_2), and this synthesis was completely blocked by N~-monomethyl L-arginine (NMMA) (300 μM), a competitive inhibitor of nitric oxide synthase (NOS). Blockade of prostaglandin synthesis by indomethacin caused rapid dissipation of isometric developed tension (IDT) induced by BK. Blockade of NOS with NMMA had similar but less marked effects. Combining the two inhibitors produced an even more rapid decay in IDT, suggesting that BK-induced NO release maintains IDT by release of prostanoids.