Prostaglandin E 2 alters the metabolism of labelled glucose in uteri isolated from ovariectomized rats. Effects of 17-beta estradiol and indomethacin

Abstract

The effects of prostaglandins (PGs) E 1, E 2 and F 2α on the oxidation of labelled glucose in uterine strips from ovariectomized rats, were explored. Moreover, the influences of in vivo estrogenization of spayed rats and the presence in vitro of indomethacin (10 −6M) on labelled glucose metabolism by isolated uteri, were also determined. PGE 2 (10 −7M), but not PGE 1 or PGF 2α, enhanced significantly the formation of 14CO 2 from U 14C-glucose in uteri from spayed rats. After the injection of 17-beta estradiol to castrated animals prior to sacrifice the three PGs augmentated in vitro uterine glucose metabolism. In uterine strips from spayed non-estrogenized rats incubated with indomethacin, only PGE 2 (10 −7 and 10 −6 M) incremented the formation of 14CO 2 from labelled glucose, whereas PGE 1 and PGF 2α were devoid of action, whereas in uteri from ovariectomized-estrogenized animals also incubated with indomethacin, PGE 1, PGE 2 and PGF 2α enhanced significantly the metabolism of labelled glucose, as was observed in the absence of indomethacin. However, in the presence of indomethacin the magnitude of the stimulation evoked by PGs in vitro was 3 to 4 times greater than without the inhibitor of the cyclo-oxygenase. The role of estradiol modulating the actions of PGE 2 and of PGF 2α on uterine glucose metabolism and possible reasons subserving the influence of indomethacin incrementing the effects of PGs on glucose oxidation in uteri from spayed-estrogenized rats, are discussed.