心肌细胞中的丙二酰辅酶A代谢及其与脂肪酸氧化调控的相关性。

Malonyl-CoA metabolism in cardiac myocytes and its relevance to the control of fatty acid oxidation.

Awan M M, Saggerson E D

Department of Biochemistry and Molecular Biology, University College London, U.K.

Biochem J. 1993 Oct 1;295 ( Pt 1)(Pt 1):61-6. doi: 10.1042/bj2950061.

Viable myocytes were obtained from rat hearts. Oxidation of [1-14C]palmitate by these cells could be decreased by the addition of glucose (5 mM) or lactate (2 mM). In the presence of glucose, insulin decreased and adrenaline increased palmitate oxidation. 2. The myocytes contained activities of ATP citrate-lyase, acetyl-CoA carboxylase and the condensing enzyme of the fatty acid elongation system. No fatty acid synthase activity was demonstrable in myocytes. 3. In rat hearts perfused with 5 mM glucose, malonyl-CoA content was acutely raised by insulin. In the presence of glucose+insulin, perfusion with palmitate or adrenaline decreased the malonyl-CoA content. 4. It is concluded that malonyl-CoA can be synthesized within cardiac myocytes and that the level of this metabolite can be acutely regulated. This is likely to have consequences for the regulation of carnitine palmitoyltransferase in the heart.

从大鼠心脏获取有活力的心肌细胞。添加葡萄糖（5 mM）或乳酸（2 mM）可降低这些细胞对[1-14C]棕榈酸的氧化。在有葡萄糖存在的情况下，胰岛素可降低而肾上腺素可增加棕榈酸氧化。2. 心肌细胞含有ATP柠檬酸裂解酶、乙酰辅酶A羧化酶以及脂肪酸延长系统的缩合酶活性。在心肌细胞中未检测到脂肪酸合酶活性。3. 在灌注5 mM葡萄糖的大鼠心脏中，胰岛素可使丙二酰辅酶A含量急剧升高。在有葡萄糖 + 胰岛素存在的情况下，用棕榈酸或肾上腺素灌注可降低丙二酰辅酶A含量。4. 得出的结论是，丙二酰辅酶A可在心肌细胞内合成，且该代谢物的水平可被急性调节。这可能对心脏中肉碱棕榈酰转移酶的调节产生影响。

Malonyl-CoA metabolism in cardiac myocytes and its relevance to the control of fatty acid oxidation.