THE ROLE OF NITRIC-OXIDE IN THE METABOLISM OF LABELED GLUCOSE IN ISOLATED RAT UTERUS - INFLUENCE OF 17-BETA-ESTRADIOL

The influence of nitric oxide (NO) on the production of (CO2)-C-14 fro m labeled glucose in uteri isolated from ovariectomized-estrogenized r ats was studied. Nitroprusside, an NO donor (NP), 200 mu M increased t he formation of labeled CO2 from [U-C-14]glucose. This effect was blun ted by hemoglobin (Hb) 20 mu g/mL, an NO scavenger. The addition of N- monomethyl arginine (NMMA), an inhibitor of NO synthase decreased the stimulatory action of NP at 400 mM. Incubation of uterine strips in th e presence of NP plus acetylsalicylic acid (ASA) 10(-4) M (a cyclooxyg enase inhibitor), inhibited the stimulatory action of NP on glucose me tabolism. PGE(2) (10(-7) M) added to the incubation medium containing NP and ASA reversed the effect of the inhibitor. Neither NP nor Hb nor NMMA modified the (CO2)-C-14 production from labeled glucose in uteri ne strips from ovariectomized rats. The addition of NP to the incubati ng medium increased PGE accumulation by uterine strips from rats treat ed with estradiol, but not in ovariectomized animals. These results su ggest that NO exerts a positive influence on glucose metabolism and PG E synthesis in isolated rat uteri from estrogenized animals.