MECHANISM OF TRANSLOCATION OF PYRUVATE AND OTHER MONOCARBOXYLIC ACIDS IN RAT-LIVER MITOCHONDRIA
MECHANISM OF TRANSLOCATION OF PYRUVATE AND OTHER MONOCARBOXYLIC ACIDS IN RAT-LIVER MITOCHONDRIA
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DOI：
10.1111/j.1432-1033.1974.tb03831.x
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发表时间：
1974-01-01
期刊：
影响因子：
--
通讯作者：
PARADIES, G
中科院分区：
文献类型：
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作者：
PAPA, S;PARADIES, G
1Pyruvate equilibrates, like other carboxylic acids, across the membrane of rat‐liver mitochondria according to the transmembrane pH difference.2Comparison of the rate of pyruvate, acetoacetate and acetate efflux from mitochondria as well as a study of the effect of mersalyl andN‐ethylmaleimide on this process, show that the diffusion of pyruvic and acetoacetic acid across the mitochondrial membrane is carrier‐mediated. The process might consist of pyruvate (acetoacetate) hydroxyl ion exchange‐diffusion or of pyruvic acid (acetoacetic acid) uniport. On the contrary acetic acid appears to diffuse freely across the membrane.3The initial rate of the net pyruvate uptake by rat liver mitochondria follows saturation kinetics. The increase of the external pH of the medium as well as the addition of acetoacetate inhibit competitively pyruvate uptake. Pyruvate uptake is inhibited by mersalyl andN‐ethylmaleimide.4Mitochondria1 [14C]pyruvate exchanges with unlabelled pyruvate and acetoacetate but not with other monocarboxylates, Piand citric‐acid cycle intermediates.5The pyruvate‐pyruvate and pyruvate‐acetoacetate exchanges follow saturation kinetics and exhibit the sameVbut differentKmvalues. Both the exchanges are inhibited by mersalyl, but not byN‐ethylmaleimide.6It is concluded that pyruvate translocation across the mitochondrial membrane is mediated by a specific transport system.
