UNCOUPLING OF THE OXIDATIVE PHOSPHORYLATION WITH CORTISONE IN LIVER MITOCHONDRIA11

Publisher Website
Google Scholar
Abstract
Oxidative phosphorylation was determined in the liver mitochondria of control rats and in young, middle-aged and old rats of both sexes treated for 7 days with 5 mg. cortisone acetate. Isocitric, [alpha]-ketoglutaric, succinic, malic and pyruvic acid were used as substrates. A total of 172 rats were used. The technique is described in detail. When the substrate was isocitrateor a-ketoglutarate, oxygen consumption was significantly decreased in old female rats. The phosphorus utilization obtained with the same acids declined in most cases, most strongly in old female animals. With succinate, malate and pyruvate the utilization of phosphorus in male rats was variably inhibited. In female rats there was a significant decrease only in old animals, and it was mostly highly significant. The P/O ratio was reduced in young female and old male rats, particularly in old females. It may be concluded that cortisone frequently inhibits oxidative phosphorylation in liver mitochondria in rats of all ages and both sexes, most strongly in females over 12 months old. Estradiol, injected simultaneously with the cortisone into old female rats, counteracts the uncoupling effect of cortisone. Growth hormone, androgenic hormone and testosterone produced no effect. Uncoupling of the oxidative phosphorylation by cortisone and inhibition of the associated ATP (adenosine triphosphate) production seems to provide an explanation for many of the tissue changes and clinical symptoms caused by cortisone.

This publication has 0 references indexed in Scilit: