The effect of oestrogens and chemically related compounds on the respiration of yeast and on oxidative phosphorylation

Abstract

Effect on endogenous respiration of yeast cells of stilboestrol, compounds chemically related to it, and some naturally occurring oestrogens, was investigated. The increase in yeast-cell respiration caused by stilboestrol and related compounds was not only a property of the biologically active substances, but depended on the chemical structure of the compounds. The natural oestrogens, oestrone and oestradiol, had no effect on the rate of O2 uptake of yeast cells. When yeast cells were respiring in the presence of acetate or ethanol, the O2 uptake was inhibited by stilboestrol. In the presence of glutamate, stilboestrol had no effect on yeast respiration. Substances which increased yeast-cell respiration were shown to uncouple oxidation from phosphorylation in cyclpphorase preparations. Myosin adenosine triphosphatase is strongly inhibited by stilboestrol and related compounds. This inhibition is probably of the non-competitive type.