Lynch R M, Paul R J
Experientia. 1985 Aug 15;41(8):970-7. doi: 10.1007/BF01952116.
Early investigations into the nature of the coupling between energy transduction and metabolism in smooth muscle, particularly from the laboratories of Bülbring and Lundholm, suggested that specific metabolic pathways could independently supply energy for ion transport and actin-myosin interactions. Subsequent work has solidified the concept that oxidative phosphorylation is specifically coupled to tension generation and maintenance, whereas, aerobic glycolysis is not only a vital characteristic of smooth muscle metabolism, but also is likely to be independently coupled to Na-K transport at the plasmalemma. The independence of oxidative and glycolytic metabolism is reflected as a compartmentation of carbohydrate metabolism in the porcine carotid artery. The coupling of these independent metabolic pathways with specific energy utilizing processes, indicates a means by which energy production and transduction can be closely and efficiently regulated. The coupling of glycogenolysis to mitochondrial respiration may have evolved as a direct response to the energetic needs of VSM. That is, the large glycogenolytic response in the initial minutes of stimulation may be necessary to maximize the cellular production of ATP during the presteady state. Likewise, the coupling between aerobic glycolysis and Na-K transport indicates a sensitive and efficient means of coordinating energy metabolism with ion transport at the membrane level. Additionally, the regulation of substrate supply, i.e. glucose transport, also may be closely coordinated with changes in ion transport. One may speculate that alterations in the microenvironment of each compartment can independently regulate intermediary metabolism and therefore allow the cell to quickly and efficiently respond to localized stimuli. Thus, stimulation of Na-K transport could effectively regulate energy production at the membrane level without mobilizing or competing with the energy transduction of other cellular processes. This compartmentation of energy utilization may be highly advantageous, since oxidative metabolism is closely coordinated with mechanical activity and therefore regulation of blood flow. Future investigations will attempt to elucidate which intracellular signals which are responsible for the regulation of these functionally independent compartments of energy metabolism and transduction in VSM. In more general terms, our findings provide a basis from which future questions concerning the regulation of cellular metabolism must be directed. The cellular cytoplasm can no longer be envisioned as a homogeneous compartment, but rather a complex array of functional subcompartments which may be individual
早期对平滑肌能量转导与代谢之间耦合性质的研究，尤其是来自比尔布林和伦德霍尔姆实验室的研究表明，特定的代谢途径可以独立地为离子转运和肌动蛋白-肌球蛋白相互作用提供能量。随后的研究巩固了这样一种概念，即氧化磷酸化与张力的产生和维持特异性耦合，而有氧糖酵解不仅是平滑肌代谢的一个重要特征，而且可能独立地与质膜上的钠钾转运耦合。氧化代谢和糖酵解代谢的独立性在猪颈动脉中表现为碳水化合物代谢的区室化。这些独立的代谢途径与特定能量利用过程的耦合，表明了一种可以密切且有效地调节能量产生和转导的方式。糖原分解与线粒体呼吸的耦合可能是作为对血管平滑肌（VSM）能量需求的直接反应而进化而来的。也就是说，在刺激开始的最初几分钟内出现的大量糖原分解反应，对于在预稳态期间使细胞内ATP的产生最大化可能是必要的。同样，有氧糖酵解与钠钾转运之间的耦合表明了一种在膜水平上协调能量代谢与离子转运的灵敏且有效的方式。此外，底物供应（即葡萄糖转运）的调节也可能与离子转运的变化密切协调。人们可以推测，每个区室微环境的改变可以独立地调节中间代谢，从而使细胞能够快速且有效地对局部刺激做出反应。因此，钠钾转运的刺激可以有效地在膜水平上调节能量产生，而无需调动或与其他细胞过程的能量转导竞争。这种能量利用的区室化可能具有高度的优势，因为氧化代谢与机械活动密切协调，进而与血流调节密切相关。未来的研究将试图阐明哪些细胞内信号负责调节血管平滑肌中这些功能上独立的能量代谢和转导区室。更一般地说，我们的发现为未来关于细胞代谢调节的问题提供了一个必须指向的基础。细胞细胞质不能再被设想为一个均匀的区室，而应是一个由功能性亚区室组成的复杂阵列，这些亚区室可能是独立的。
