Glycerophosphate-Dependent Hydrogen Peroxide Production by Rat Liver Mitochondria

P. JEŠINA, D. KHOLOVÁ¹, R. BOLEHOVSKÁ¹, Z. ČERVINKOVÁ¹,
Z. DRAHOTA, J. HOUŠTĚK

Center for Integrated Genomics, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, ¹Department of Physiology, Faculty of Medicine, Charles University, Hradec Králové, Czech Republic

Received March 5, 2003
Accepted July 21, 2003


Summary
We studied the extent to which hormonally-induced mitochondrial glycerophosphate dehydrogenase (mGPDH) activity contributes to the supply of reducing equivalents to the mitochondrial respiratory chain in the rat liver. The activity of glycerophosphate oxidase was compared with those of NADH oxidase and/or succinate oxidase. It was found that triiodothyronine-activated mGPDH represents almost the same capacity for the saturation of the respiratory chain as Complex II. Furthermore, the increase of mGPDH activity induced by triiodothyronine correlated with an increase of capacity for glycerophosphate-dependent hydrogen peroxide production. As a result of hormonal treatment, a 3-fold increase in glycerophosphate-dependent hydrogen peroxide production by liver mitochondria was detected by polarographic and luminometric measurements.


Key words
Rat liver mitochondria • Mitochondrial glycerophosphate dehydrogenase • Triiodothyronine • Hydrogen peroxide