THE EFFECT OF a-ESTRADIOL, SOME OF ITS ESTERS AND ESTRONE ON THE RESPIRATION OF TISSUE HOMOGENATES1

Abstract

MEYER et al. (1948) showed that certain natural and synthetic estrogens in concentrations of 0.2 to 3 × 10⁻⁴ M inhibit tissue respiration by attacking the iron compounds in the cytochrome system. The portion of the estrogenic molecule responsible for this inhibition was traced to the free phenolic groups of these compounds. Case and Dickens (1948) described some synthetic estrogens which inhibit the succinoxidase by acting on the cytochrome portion, some which inhibit by acting on the succinic dehydrogenase system, and still others which inhibit the over-all oxidation of succinate but which act neither on the cytochrome oxidase nor the succinic dehydrogenase. Data are herein reported which suggest a-estradiol, some of its esters, and estrone in a concentration of 5 × 10⁻⁵ M inhibit oxidation of substrates whose oxidative systems are coenzyme linked but do not inhibit the succinoxidase system. MATERIALS AND METHODS