COMPARTMENTATION OF CARBOHYDRATE-METABOLISM IN VASCULAR SMOOTH-MUSCLE
COMPARTMENTATION OF CARBOHYDRATE-METABOLISM IN VASCULAR SMOOTH-MUSCLE
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DOI：
10.1152/ajpcell.1987.252.3.c328
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发表时间：
1987-03-01
影响因子：
--
通讯作者：
PAUL, RJ
中科院分区：
文献类型：
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作者：
LYNCH, RM;PAUL, RJ
在血管平滑肌中，氧化磷酸化和糖酵解独立调节。先前的研究表明，这些途径的独立调节与碳水化合物代谢的区室化有关。为了进一步研究碳水化合物代谢，在氧化和糖酵解途径独立改变后，测量葡萄糖转运和从葡萄糖到糖原和乳酸的放射性标记掺入。哇巴因刺激机械活动，耗氧量和糖原分解，而乳酸产生减少。虽然糖原分解是实质性的，葡萄糖是乳酸的唯一底物，表明来自糖原的中间体不与来自葡萄糖摄取的中间体混合。因此，糖原分解和糖酵解通过独立的酶途径进行。胰岛素刺激乳酸产生和葡萄糖转运，而不影响其他参数。同样，乳酸仅由葡萄糖产生。 苯妥英钠降低等长收缩张力和氧耗，而刺激乳酸产生和糖原分解。糖原是产生乳酸的主要底物。我们的研究结果表明，底物利用的区室化是由于糖原分解与耗氧量增加的协调和糖酵解与Na-K-腺苷三磷酸酶的耦合。独立的能量提供途径与特定的吸能过程的耦合表明，这些过程表明可以优化细胞能量效率的机制。
In vascular smooth muscle, oxidative phosphorylation and glycolysis are independently regulated. Previous studies indicated that the independent regulation of these pathways was related to a compartmentation of carbohydrate metabolism. To further study carbohydrate metabolism, glucose transport and the incorporation of radiolabel from glucose into glycogen and lactate were measured after the oxidative and glycolytic pathways were independently altered. Ouabain stimulated mechanical activity, oxygen consumption, and glycogenolysis, whereas lactate production was decreased. Although glycogenolysis was substantial, glucose was the only substrate for lactate, indicating that intermediates derived from glycogen do not mix with those from glucose uptake. Thus glycogenolysis and glycolysis are carried out by independent enzymatic pathways. Insulin-stimulated lactate production and glucose transport without affecting the other parameters. Again, lactate was produced only from glucose. Phenytoin decreased isometric tension and oxygen consumption, whereas stimulating lactate production and glycogenolysis. Glycogen was the primary substrate for the lactate produced. Our findings indicate that the compartmentation of substrate utilization is ascribable to the coordination of glycogenolysis with increases in oxygen consumption and the coupling of glycolysis to the Na-K-adenosine triphosphatase. The coupling of independent energy providing pathways to specific endergonic processes indicates processes indicates a mechanism by which cellular energetic efficiency may be optimized.