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[Calcium-activated chloride channels are involved in two-phase hypoxic pulmonary vasoconstriction in rat pulmonary arteries.] [Article in Chinese]

YING Lei, YAO Hai-Xia, HUANG Lin-Jing, MA Ying-Chun, HE Jin-Bo, CHEN Dan, CHEN Hai-E, WANG Yang, WANG Wan-Tie

Department of Pathophysiology； Institute of Ischemia-reperfusion Injury,Wenzhou Medical University, Wenzhou 325035, China； Department of Anesthesiology, The Sixth People’s Hospital of Shanghai , Shanghai 200233 , China

Abstract

The aim of the present study was to investigate the roles of calcium-activated chloride channels (Cl_Ca) in the two-phase hypoxic pulmonary vasoconstriction (HPV). The second pulmonary artery branches were dissected from male Sprague-Dawley rats, and the changes in vascular tone were measured by using routine blood vascular perfusion in vitro. The result showed that, under normoxic conditions, Cl_Ca inhibitors (NFA and IAA-94) significantly relaxed second pulmonary artery contracted by norepinephrine (P < 0.01), but merely had effects on KCl-induced second pulmonary artery contractions. A biphasic contraction response was induced in second pulmonary artery ring pre-contracted with norepinephrine exposed to hypoxic conditions for at least one hour, but no biphasic contraction was observed in pulmonary rings pre-contracted with KCl. NFA and IAA-94 significantly attenuated phase II sustained hypoxic contraction (P < 0.01), and also attenuated phase I vasodilation, but had little effect on phase I contraction. These results suggest that Cl_Ca is an important component forming phase II contraction in secondary pulmonary artery, but not involved in phase I contraction.

Key words: Calcium-activated chloride channels; pulmonary artery; Hypoxic pulmonary vasoconstriction

Received: 2013-08-14　　Accepted: 2014-01-07

Corresponding author: 王万铁　　E-mail: wzwwt@tom.com

Citing This Article：

YING Lei, YAO Hai-Xia, HUANG Lin-Jing, MA Ying-Chun, HE Jin-Bo, CHEN Dan, CHEN Hai-E, WANG Yang, WANG Wan-Tie. [Calcium-activated chloride channels are involved in two-phase hypoxic pulmonary vasoconstriction in rat pulmonary arteries.] [Article in Chinese]. Acta Physiol Sin 2014; 66 (2): 203-209 (in Chinese with English abstract).