Location of the estrogen effect on uterine glucose metabolism.

Abstract

SummaryMeasurements of incorporation of 14C from differentially labelled glucose and pyruvate into uterine lipid and CO2 were used to evaluate early metabolic changes produced by estradiol in immature rat uterus. Tissue was incubated with the isotopes in vitro after hormone treatment in vivo. With pyruvate-3-14C as substrate, substantially more 14CO2 is produced than with glucose-1-14C or glu-cose-6-14C as substrates. Also, 14CO2 output from glucose-1-14C is about double that from glucose-6-14C. Estradiol treatment causes a similar increase of 14C incorporation into lipid with either of the glucose substrates or with pyruvate. This suggests that the estradiol effect on lipid synthesis is beyond pyruvate. A differential effect on 14CO2 production from glucose and pyruvate, however, locates an estradiol effect between these substrates. Furthermore, the estradiol acceleration of 14CO2 production from glucose-1-14C and glucose-6-14C is equal. This suggests that the site of estrogen stimulation of uterine gluc...