Oxidation of glycerol-3-phosphate in porcine and bovine adrenal cortex mitochondria

The capabilities of porcine adrenal cortex mitochondria to oxidize glycerol-3-phos- phate (GP) were studied. In comparison with bovine adrenal cortex mitochondria, porcine mitochondria oxidized GP about three times more actively (18.9 vs 6.1 nmol O2/min per mg protein in the presence of ADP) and the activity of mitochondrial glycerol-3-phosphate dehydrogenase was about four times higher (33.4 vs 8.2 nmol/min per mg protein). In porcine adrenal cortex mitochondria we found similar values for succinate and GP oxidation both in the absence and presence of ADP or deoxycorticosterone (DOC). Rotenone sensitivity of DOC stimulation of GP oxidation indicated that porcine adrenal cortex mitochondria are able to oxidize GP and thus to generate NADPH from GP, presumably via reverse electron transport followed by energy-dependent NADH-NADP transhydrogenation.