AJP - Endocrinology and Metabolism, Vol 246, Issue 3 288-E291, Copyright © 1984 by American Physiological Society
Estrogen-like stimulation of uterine ornithine decarboxylase by cholera toxin
R. A. Webster, C. J. Zaloudek, B. C. Inman and P. J. Stewart
Cholera toxin administered by intrauterine injection to ovariectomized rats
increased uterine ornithine decarboxylase activity as much as systemic
estradiol at 4 h after treatment. At 45-60 min after treatment, however,
cholera toxin did not increase nuclear estrogen receptor or stimulate
synthesis of the uterine "induced protein," which is closely correlated
with nuclear receptor, whereas estradiol caused substantial increases in
both nuclear receptor and induced protein synthesis. Intrauterine injection
of cholera toxin also produced an estrogen-like elevation of the uterine
protein/DNA ratio at 24 h. Because both cholera toxin and estradiol are
known to increase vascular permeability, our results support the hypothesis
that some uterine effects of estradiol are not mediated by receptor-genome
interaction but involve another mechanism that is associated with increased
vascular permeability.
