KATP channels are an important component of the shear-sensing mechanism in the pulmonary microvasculature

被引:58
作者
Chatterjee, S.
Levitan, I.
Wei, Z.
Fisher, A. B.
机构
[1] Univ Penn, Sch Med, Inst Environm Med, Philadelphia, PA 19104 USA
[2] Univ Penn, Inst Med & Engn, Philadelphia, PA 19104 USA
关键词
calcium influx; K(IR)6.2; lung ischemia; mechanotransduction; membrane depolarization; patch clamp; superoxide;
D O I
10.1080/10739680600930255
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
Objective: To investigate the role of a K-ATP channel in sensing shear, specifically its cessation, in the endothelial cells of the pulmonary microvasculature. Methods: Endothelial cells isolated from the pulmonary microvasculature of wild-type and K-ATP channel knockout (K(IR)6.2-/-) mice were either statically cultured (non-flow-adapted) or kept under flow (flow-adapted) and the K-IR currents in these cells were monitored by whole-cell patch-clamp technique during flow and its cessation. Membrane potential changes, generation of reactive oxygen species (ROS), and Ca2+ influx with flow cessation were evaluated by the use of fluorescent dyes. Lungs isolated from wild-type mice were imaged to visualize ROS generation in the subpleural endothelium. Results: By patch-clamp analysis, reduction in the K-IR current with cessation of flow occurred only in wild-type cells that were flow-adapted and not in flow-adapted K(IR)6.2(-/-) cells. Similar observations were made using changes in bisoxonol fluorescence as an index of cell membrane potential. Generation of ROS and Ca2+ influx that follow membrane depolarization were significantly lower in statically cultured and in K(IR)6.2(-/-) cells as compared to flow-adapted wild-type cells. Imaging of subpleural endothelial cells of the whole lung showed that the K-ATP antagonist glyburide caused the production of ROS in the absence of flow cessation. Conclusions: The responses to stop of flow (viz. membrane depolarization, K-IR currents, ROS, Ca2+) were significantly altered with knockout of K-ATP channels, which indicates that this channel is an important component of the pulmonary endothelial response to abrupt loss of shear stress.
引用
收藏
页码:633 / 644
页数:12
相关论文
共 48 条
[1]   Toward understanding the assembly and structure of KATP channels [J].
Aguilar-Bryan, L ;
Clement, JP ;
Gonzalez, G ;
Kunjilwar, K ;
Babenko, A ;
Bryan, J .
PHYSIOLOGICAL REVIEWS, 1998, 78 (01) :227-245
[2]   ATP-independent membrane depolarization with ischemia in the oxygen-ventilated isolated rat lung [J].
Al-Mehdi, AB ;
Zhao, GC ;
Fisher, AB .
AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY, 1998, 18 (05) :653-661
[3]   Ca2+- and phosphatidylinositol 3-kinase-dependent nitric oxide generation in lung endothelial cells in situ with ischemia [J].
Al-Mehdi, AB ;
Song, C ;
Tozawa, K ;
Fisher, AB .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2000, 275 (51) :39807-39810
[4]   Endothelial NADPH oxidase as the source of oxidants in lungs exposed to ischemia or high K+ [J].
Al-Mehdi, AB ;
Zhao, GC ;
Dodia, C ;
Tozawa, K ;
Costa, K ;
Muzykantov, V ;
Ross, C ;
Blecha, F ;
Dinauer, M ;
Fisher, AB .
CIRCULATION RESEARCH, 1998, 83 (07) :730-737
[5]   Oxidant generation with K+-induced depolarization in the isolated perfused lung [J].
AlMehdi, AB ;
Shuman, H ;
Fisher, AB .
FREE RADICAL BIOLOGY AND MEDICINE, 1997, 23 (01) :47-56
[6]  
AlMehdi AB, 1996, J CELL PHYSIOL, V166, P274, DOI 10.1002/(SICI)1097-4652(199602)166:2<274::AID-JCP4>3.0.CO
[7]  
2-M
[8]   Intracellular generation of reactive oxygen species during nonhypoxic lung ischemia [J].
AlMehdi, AB ;
Shuman, H ;
Fisher, AB .
AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY, 1997, 272 (02) :L294-L300
[9]   Reconstituted human cardiac KATP channels -: Functional identity with the native channels from the sarcolemma of human ventricular cells [J].
Babenko, AP ;
Gonzalez, G ;
Aguilar-Bryan, L ;
Bryan, J .
CIRCULATION RESEARCH, 1998, 83 (11) :1132-1143
[10]   A flow-activated chloride-selective membrane current in vascular endothelial cells [J].
Barakat, AI ;
Leaver, EV ;
Pappone, PA ;
Davies, PF .
CIRCULATION RESEARCH, 1999, 85 (09) :820-828