ESTROGEN STIMULATION OF THE OVIDUCT IN VITAMIN-DEFICIENT CHICKS1

Abstract

The inanition which accompanies a state of vitamin deficiency is responsible for a nonspecific, reduced sensitivity of the oviduct to the action of estrogen. When this reduced sensitivity is taken into consideration it is found that estrogen exerts a greater than expected stimulation in thiamine-deficient pullets. In riboflavin-deficient pullets the reduced response to estrogen may be accounted for, superficially at least, on the basis of inanition alone but may be the algebraic sum of numerous factors such as reduced inactivation of estrogen and decreased functioning of the mechanisms for tissue proliferation. In nicotinic acid-deficient pullets low doses of estrogen can exert a greater than expected influence on oviduct growth but high doses are less effective than in inanition controls. A deficiency of pteroylglutamic acid (PGA), however, results in a severe limitation of response to estrogen at all dose levels. The implication is that PGA is essential to the mechanism of action of estrogen in promoting tissue proliferation in the chick oviduct at the level of the end organ itself. The naturally occurring estrogen, estrone, is similar to the synthetic stilbestrol in that it also does not effect an optimal stimulation of the oviduct in chicks deficient in PGA.