Hardin C D, Wiseman R W, Kushmerick M J
Department of Radiology, University of Washington, Seattle.
Biochim Biophys Acta. 1992 Jan 13;1133(2):133-41. doi: 10.1016/0167-4889(92)90060-o.
Control of respiration in vascular smooth muscle was examined while the metabolic state of the tissue was manipulated. During KCl-induced contractures in the presence of 5 mM glucose, oxygen consumption increased by 10 nmol/per min g without any decrease in phosphocreatine (PCr) or ATP as determined by 31P-NMR indicating a control of respiration which does not involve changes in high-energy phosphates (e.g., ADP, phosphorylation potential). However, when aortae with resting tone in the absence of substrate were then provided with 5 mM 2-deoxyglucose as the sole substrate, oxygen consumption increased 7.4 nmol/min per g while PCr decreased by more than 50% (resulting in a 2-fold increase in the calculated free ADP) with no change in tension from resting tone. During a subsequent KCl induced contracture in the presence of 2-deoxyglucose, oxygen consumption increased an additional 7.2 nmol/min per g while PCr continued to decline. Therefore, at least two mechanisms of respiratory control may exist in sheep aorta, one dependent and the other independent of changes in high-energy phosphates.
在对组织的代谢状态进行调控的同时，研究了血管平滑肌中呼吸的控制情况。在存在5 mM葡萄糖的情况下，由氯化钾诱导挛缩期间，通过31P-NMR测定，氧消耗量增加了10 nmol/每分钟每克，而磷酸肌酸（PCr）或三磷酸腺苷（ATP）没有任何减少，这表明呼吸的控制并不涉及高能磷酸盐（例如，二磷酸腺苷（ADP）、磷酸化电位）的变化。然而，当在没有底物的情况下具有静息张力的主动脉随后被提供5 mM 2-脱氧葡萄糖作为唯一底物时，氧消耗量增加了7.4 nmol/每分钟每克，而PCr下降了超过50%（导致计算出的游离ADP增加了两倍），张力与静息张力相比没有变化。在随后存在2-脱氧葡萄糖的情况下由氯化钾诱导挛缩期间，氧消耗量又增加了7.2 nmol/每分钟每克，而PCr继续下降。因此，在绵羊主动脉中可能存在至少两种呼吸控制机制，一种依赖于高能磷酸盐的变化，另一种独立于高能磷酸盐的变化。
