缺氧内皮超滤液对正常人心肌横桥功能的抑制作用。

Inhibition of crossbridge function in the normal human heart by hypoxic endothelial superfusate.

作者信息

Zacharzowsky U B, Shah A M, Haase H, Morano I

机构信息

Charité, Campus Berlin-Buch, Franz-Volhard-Clinic, Humboldt-University of Berlin, Berlin, 13122, Germany.

出版信息

Biochem Biophys Res Commun. 1999 Aug 19;262(1):64-7. doi: 10.1006/bbrc.1999.1058.

DOI:10.1006/bbrc.1999.1058

PMID:10448069

Abstract

Endothelial cells release diffusible substances which modulate myocardial function. Oxygen pressure is one important factor for stimulation and modulation of endothelial function. Here we investigated the effects of a superfusate obtained from hypoxic (pO(2) 40-50 mmHg) porcine endothelial cell culture on human myocardial crossbridge cycling rate. Isometric force development and the rate constant for tension development of demembranated multicellular fibers from the left myocardium of a normal human heart were determined from the low-tension rigor by photolytic release of ATP from caged-ATP. Incubation with hypoxic or normoxic superfusates did not change maximal isometric force development. However, rate constant of tension development of the normal human heart fibers significantly decreased to 43.3% upon incubation with the hypoxic but not normoxic endothelial cell superfusate.

摘要

内皮细胞释放可扩散物质，调节心肌功能。氧分压是刺激和调节内皮功能的一个重要因素。在此，我们研究了从低氧（pO₂ 40 - 50 mmHg）猪内皮细胞培养物中获得的灌流液对人心肌横桥循环速率的影响。通过从笼形ATP光解释放ATP，从正常人心左心室去膜多细胞纤维的低张力强直状态测定等长力发展以及张力发展速率常数。用低氧或常氧灌流液孵育并未改变最大等长力发展。然而，与低氧而非常氧内皮细胞灌流液孵育后，正常人心肌纤维的张力发展速率常数显著降至43.3%。