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Glycerol-1-phosphate — supported respiratory activity of porcine adrenal cortex mitochondria

100%

Popinigis J., Antosiewicz J., Kaczor J., Rauchova H., Lenaz G.

Acta Biochimica Polonica

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2003

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tom 50

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nr Supplement 1

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

100%

Popinigis J., Antosiewicz J., Kaczor J. J., Rauchova H., Lenaz G.

Acta Biochimica Polonica

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2004

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tom 51

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nr 4

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.

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Coenzyme Q releases the inhibitory effect of free fatty acids on mitochondrial glycerophosphate dehydrogenase

100%

Rauchova H., Drahota Z., Rauch P., Fato R., Lenaz G.

Acta Biochimica Polonica

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2003

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tom 50

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nr 2

Data presented in this paper show that the size of the endogenous coenzyme Q (CoQ) pool is not a limiting factor in the activation of mitochondrial glyceropho- sphate-dependent respiration by exogenous CoQ3, since successive additions of succinate and NADH to brown adipose tissue mitochondria further increase the rate of oxygen uptake. Because the inhibition of glycerophosphate-dependent respiration by oleate was eliminated by added CoQ3, our data indicate that the activating effect of CoQ3 is related to the release of the inhibitory effect of endogenous free fatty acids (FFA). Both the inhibitory effect of FFA and the activating effect of CoQ3 could be demonstrated only for glycerophosphate-dependent respiration, while succinate- or NADH-dependent respiration was not affected. The presented data suggest differences between mitochondrial glycerophosphate dehydrogenase and succinate or NADH dehydrogenases in the transfer of reducing equivalents to the CoQ pool.

Ograniczanie wyników

3 Acta Biochimica Polonica

3 Lenaz G.

3 Rauchova H.

2 Antosiewicz J.

2 Popinigis J.

1 Drahota Z.

1 Fato R.

1 Kaczor J.

1 Kaczor J. J.

1 Rauch P.

1 2004

2 2003

Glycerol-1-phosphate — supported respiratory activity of porcine adrenal cortex mitochondria

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

Coenzyme Q releases the inhibitory effect of free fatty acids on mitochondrial glycerophosphate dehydrogenase