1. 1. Dehydroepiandrosterone (DHEA) inhibited mitochondrial respiratory rates in the presence of tricarboxylic acid cycle intermediates with the exception of succinate. 2. 2. Several other steroids tested for inhibitory activity on mitochondrial state 3 rate showed inhibitory potencies ranging from 0-90%. 3. 3. Mitochondria isolated from adrenals, heart, kidneys, brain and brown adipose tissue were also inhibited by DHEA. 4. 4. The aspartate-malate shuttle system was inhibited, but the α-glycerophosphate shuttle was totally insensitive to DHEA. 5. 5. The high-amplitude swelling of mitochondria in hypotonic media was inhibited by DHEA and a few other steroids.
Bibliographical noteFunding Information:
Acknowledgemenfs-This work was supported by United States Public Health Service Grant HL08214 from the Program Projects Branch, Extramural Programs, National Heart, Lung and Blood Institute, and by The Hormel Foundation.