Wang X, Yang J, Dong L, Pang Y, Su J, Tang C, Liu N
Institute of Cardiovascular Research, First Hospital of Beijing Medical University, Beijing 100034.
Chin Med Sci J. 2001 Mar;16(1):10-4.
To study the redistribution of endothelin-1 (ET-1) receptors in two subcellular organelles, the sarcolemmal membrane and the light vesicle, of rat heart during the progression of sepsis.
Sepsis was induced by cecal ligation and puncture (CLP). ET1 receptor was assayed by using [125I]-ET1 binding. Marker enzyme activities, protein yield, and dry-to-wet weight ratio of cardiac membranes were measured.
Septic rat heart exhibited two distinct phases: an initial hyperdynamic phase( 9h after CLP; early stage of sepsis) followed by a hypodynamic (18h after CLP, late stage of sepsis) phase. [125I]-ET1 binding study showed that during early stage of sepsis, the B(max) of ET1 receptors was increased by 30% in sarcolemma but decreased by 19% in light vesicles, while during late stage of sepsis, the B(max) was decreased by 24% in sarcolemma but increased by 38% in light vesicles. The total binding of sarcolemma and light vesicles was increased by 25% during early stage of sepsis but decreased by 17% during late stage of sepsis.
These data indicated that ET1 receptors in the rat heart were externalized from light vesicles to sarcolemmal membranes during early hyperdynamic phase while internalized from surface membranes to intracellular compartment during late hypodynamic phase of sepsis.
研究脓毒症进展过程中大鼠心脏两个亚细胞器（肌膜和轻囊泡）中内皮素-1（ET-1）受体的重新分布。
采用盲肠结扎穿孔术（CLP）诱导脓毒症。通过[125I]-ET1结合法检测ET1受体。测量心脏膜的标志酶活性、蛋白产量和干湿重比。
脓毒症大鼠心脏表现出两个不同阶段：初始的高动力阶段（CLP后9小时；脓毒症早期），随后是低动力阶段（CLP后18小时，脓毒症晚期）。[125I]-ET1结合研究表明，在脓毒症早期，肌膜中ET1受体的B(max)增加30%，而轻囊泡中降低19%；在脓毒症晚期，肌膜中B(max)降低24%，而轻囊泡中增加38%。脓毒症早期肌膜和轻囊泡的总结合增加25%，而晚期降低17%。
这些数据表明，在脓毒症早期高动力阶段，大鼠心脏中的ET1受体从轻囊泡外化至肌膜，而在晚期低动力阶段从表面膜内化至细胞内区室。
