Effects of prostaglandins and of leukotriene C 4 on the metabolism of labelled glucose in uteri isolated from ovariectomized-diabetic rats. Influences of 17-beta-estradiol and of insulin

Abstract

The influences of exogenous PGE 1, PGE 2, PGF 2α, LTC 4 and insulin (INS) on glucose oxidation in uterine strips isolated from ovariectomized-diabetic (OVD) and ovariectomized-estrogenized-diabetic (OVED) rats, were studied. The spayed animals were made diabetic by a single injection of streptozotocin (65 mg.kg −1 body weight). The effects of prostaglandins were studied in the presence of indomethacin (INDO) in the incubation medium and the effects of LTC 4 in the presence of INDO and nordihydroguaretic acid (NDGA). These procedures were followed in order to avoid the possible influences of endogenous derivatives of arachidonic acid formed by the activity of cyclooxygenase and of lipoxygenases. INDO and NDGA did not modify significantly the formation of 14CO 2 from U- 14C-glucose in uteri from OVD and from OVED rats. INS (0.5 U.ml −1) augmented significantly labelled glucose metabolism, both in OVD as well as in OVED rats. On the other hand, added PGE 1, PGE 2, PGF 2α or LTC 4 failed to alter glucose metabolism in uteri from OVD rats. Only PGE 1 was able to increase significantly (p < 0.05) 14CO 2 production from labelled glucose in uterine strips from OVED rats. In OVD rats the stimulatory action of INS on uterine glucose metabolism was significantly enhanced by exogenous PGE 1, but not modified by PGE 2, by PGF 2α or by LTC 4. PGE 1, PGE 2 and LTC 4 sensitized uterine strips obtained from OVED rats to the effects of INS. The possible importance of PGE 1 in improving uterine glucose metabolism in diabetic animals is discussed.