Sex Hormone Control Mechanisms. I. Effect of Estrogen and Progesterone on Major Cellular Components in Chicken (Gallus domesticus) Oviducts

Abstract

The role and mode of action of sex hormones in the regulation of avian oviduct metabolism have been investigated. The oviducts of chicks treated with repeated injections of various sex hormones and of untreated hens have been analyzed for their contents of DNA, RNA, protein, lipids, glucose, and glycogen.Estrogen induces a profound growth of chick oviduct primarily by hyperplasia (increased amount of DNA). Cellular hypertrophy (indicated by the ratio dry matter/DNA) accounts for a smaller proportion of the total oviduct growth. Progesterone alone seems to have little or no effect on oviduct growth. Progesterone, in combination with estrogen, however, antagonizes the estrogen-induced hyperplasia of oviduct, but synergizes with estrogen in eliciting cellular hypertrophy. The increase of oviduct growth as influenced by the hormones is mainly contributed to by relatively proportional increases of both protein and lipids. In all cases the changes in total protein parallel the changes in total RNA, thus suggesting RNA formation as a prerequisite for hormonal induction of protein synthesis. Electrophoresis of the soluble oviduct proteins shows that there are qualitative differences among the various treatment groups. Estrogen or estrogen with low level of progesterone is needed for ovalbumin formation. Estrogen or progesterone induces significant increases in glycogen concentrations; combinations of the two hormones exhibit a synergistic effect. The hormone-stimulated synthesis of glycogen seems to depend on accelerated uptake of glucose by oviduct cells.The levels of various cellular components in the hormone-treated chicks are interpreted partially in terms of data obtained from mature hens. The results are discussed in terms of hormone control mechanisms and estrogen–progesterone interactions.