The Effect of Estrogen on the Production of a Peroxidase in the Rat Uterus

This is the authors' abstract. We don't add key points for this paper.

McShan and Meyer (1) observed an inhibition of the succinoxidase system of rat liver homogenate upon the addition of a small amount of diethylstilbestrol, hexestrol, and dienestrol.The locus of inhibition was considered to be cytochrome oxidase.Case and Dickens (2) amplified these observations by investigating a wider range of estrogens and chemically related compounds of slight estrogenic potency.The inhibition in vitro of the succinoxidase system by these compounds was found not to be correlated with estrogenic potency and the site of inhibition was not the same with the different estrogens studied.Hochster and Quastel (3) reported that oxidized diethylstilbestrol could act as a hydrogen acceptor in certain enzyme systems.In view of these findings and since this laboratory has been engaged in the separation and study of the "individual" components of the succinoxidase system (4-7), it was of interest to investigate the various components of the succinoxidase system in the rat uterus following stimulation with estrogen.During the course of this study, it was found that the injection of estrogens into the ovariectomized rat caused a pronounced activity of peroxidase in the uterus, whereas this activity was normally extremely low.Further, the peroxidase activity was related to the amount of estrogen injected. MethodsFemale rats of the Wistar strain, weighing from 180 to 200 gm., were ovariectomized under aseptic conditions.4 weeks after ovariectomy the animals were injected intramuscularly with 0.2 ml. of cottonseed oil for controls or with 0.2 ml. of a cottonseed oil solution of estrogen.The amounts of diethylstilbestrol or 17p-estradiol used for injection were 0.05, 0.10, 0.20, 0.30 mg.The rats were sacrificed by decapitation at intervals of up to 4 days after injection of the hormone.The uterus of each animal was quickly removed, stripped of visible fat, and chilled.The uteri of three rats were pooled and 20 per cent homogenates in cold 0.1 M NazHP04-KH2P04 buffer, pH 7.4, were prepared in a chilled all-glass homogenizer.