糖尿病与大鼠心脏线粒体中丙酮酸脱氢酶的调控：通过三磷酸腺苷/二磷酸腺苷、还原型/氧化型烟酰胺腺嘌呤二核苷酸以及乙酰辅酶A/辅酶A的浓度比进行调控

Diabetes and the control of pyruvate dehydrogenase in rat heart mitochondria by concentration ratios of adenosine triphosphate/adenosine diphosphate, of reduced/oxidized nicotinamide-adenine dinucleotide and of acetyl-coenzyme A/coenzyme A.

Kerbey A L, Radcliffe P M, Randle P J

Biochem J. 1977 Jun 15;164(3):509-19. doi: 10.1042/bj1640509.

Abstract

The proportion of active (dephosphorylated) pyruvate dehydrogenase in rat heart mitochondria was correlated with total concentration ratios of ATP/ADP, NADH/NAD+ and acetyl-CoA/CoA. These metabolites were measured with ATP-dependent and NADH-dependent luciferases. 2. Increase in the concentration ratio of NADH/NAD+ at constant [ATP]/[ADP] and [acetyl-CoA]/[CoA] was associated with increased phosphorylation and inactivation of pyruvate dehydrogenase. This was based on comparison between mitochondria incubated with 0.4mM- or 1mM-succinate and mitochondria incubated with 0.4mM-succinate+/-rotenone. 3. Increase in the concentration ratio acetyl-CoA/CoA at constant [ATP]/[ADP] and [NADH][NAD+] was associated with increased phosphorylation and inactivation of pyruvate dehydrogenase. This was based on comparison between incubations in 50 micrometer-palmitotoyl-L-carnitine and in 250 micrometer-2-oxoglutarate +50 micrometer-L-malate. 4. These findings are consistent with activation of the pyruvate dehydrogenase kinase reaction by high ratios of [NADH]/[NAD+] and of [acetyl-CoA]/[CoA]. 5. Comparison between mitochondria from hearts of diabetic and non-diabetic rats shows that phosphorylation and inactivation of pyruvate dehydrogenase is enhanced in alloxan-diabetes by some factor other than concentration ratios of ATP/ADP, NADH/NAD+ or acetyl-CoA/CoA.

摘要

大鼠心脏线粒体中活性（去磷酸化）丙酮酸脱氢酶的比例与ATP/ADP、NADH/NAD⁺和乙酰辅酶A/辅酶A的总浓度比值相关。这些代谢物通过依赖ATP的荧光素酶和依赖NADH的荧光素酶进行测定。2. 在[ATP]/[ADP]和[乙酰辅酶A]/[辅酶A]恒定的情况下，NADH/NAD⁺浓度比值的增加与丙酮酸脱氢酶磷酸化增加及失活相关。这是基于用0.4mM或1mM琥珀酸孵育的线粒体与用0.4mM琥珀酸±鱼藤酮孵育的线粒体之间的比较得出的。3. 在[ATP]/[ADP]和[NADH]/[NAD⁺]恒定的情况下，乙酰辅酶A/辅酶A浓度比值的增加与丙酮酸脱氢酶磷酸化增加及失活相关。这是基于在50微摩尔棕榈酰-L-肉碱和250微摩尔2-氧代戊二酸+50微摩尔L-苹果酸中孵育的比较得出的。4. 这些发现与高比值的[NADH]/[NAD⁺]和[乙酰辅酶A]/[辅酶A]激活丙酮酸脱氢酶激酶反应一致。5. 糖尿病大鼠和非糖尿病大鼠心脏线粒体的比较表明，在四氧嘧啶糖尿病中，丙酮酸脱氢酶的磷酸化和失活因ATP/ADP、NADH/NAD⁺或乙酰辅酶A/辅酶A浓度比值以外的某些因素而增强。