Barron J T, Gu L
Section of Cardiology, Department of Internal Medicine, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA.
Am J Physiol Heart Circ Physiol. 2000 Jan;278(1):H26-32. doi: 10.1152/ajpheart.2000.278.1.H26.
Adenosine (Ado) is a naturally occurring compound that has several important cardiovascular actions, including activation of ATP-sensitive K(+) channels in vascular smooth muscle, vasorelaxation, and an effect to alter glucose metabolism of cardiac muscle. The metabolic effects of Ado on vascular smooth muscle have not been defined and were examined in this study. Porcine carotid artery strips were incubated in the presence and absence of 0.5 mM Ado. Compared with the control, Ado had no effect on glucose uptake, glucose oxidation, or fatty acid (octanoate) oxidation. Ado suppressed glycolysis but enhanced glycogen synthesis. Relative to the rate of glycolysis, Ado increased lactate production. Ado stimulated O(2) consumption by 52 +/- 10%, altered the activities of the tricarboxylic acid cycle and malate-aspartate shuttle, and increased the content of ATP, ADP, AMP, and phosphocreatine. Alteration in the metabolic variables by Ado could not be attributed to diminished energy requirements of reduced resting muscle tone of the arterial strips. Relaxation of the arterial strips in response to Ado were abolished in arteries incubated under hypoxic conditions (95% N(2)-5% CO(2)). Hypoxia was associated with increased ADP content. It is concluded that Ado affected glucose metabolism indirectly. The metabolic and energetic effects of 0.5 mM Ado are mediated by alterations in the concentrations of AMP, ATP, and phosphorylation potential (ATP/ADP).
腺苷（Ado）是一种天然存在的化合物，具有多种重要的心血管作用，包括激活血管平滑肌中的ATP敏感性钾通道、血管舒张以及改变心肌葡萄糖代谢的作用。Ado对血管平滑肌的代谢作用尚未明确，本研究对此进行了探讨。将猪颈动脉条分别置于含有和不含0.5 mM Ado的环境中孵育。与对照组相比，Ado对葡萄糖摄取、葡萄糖氧化或脂肪酸（辛酸）氧化均无影响。Ado抑制糖酵解但增强糖原合成。相对于糖酵解速率，Ado增加乳酸生成。Ado使耗氧量增加52±10%，改变三羧酸循环和苹果酸-天冬氨酸穿梭的活性，并增加ATP、ADP、AMP和磷酸肌酸的含量。Ado引起的代谢变量改变并非归因于动脉条静息肌张力降低导致的能量需求减少。在缺氧条件（95% N₂-5% CO₂）下孵育的动脉中，对Ado产生反应的动脉条舒张作用消失。缺氧与ADP含量增加有关。得出的结论是，Ado间接影响葡萄糖代谢。0.5 mM Ado的代谢和能量作用是由AMP、ATP浓度及磷酸化电位（ATP/ADP）的改变介导的。
