Calcium-activated chloride channels are involved in two-phase hypoxic pulmonary vasoconstriction in rat pulmonary arteries / 生理学报
Acta Physiologica Sinica
; (6): 203-209, 2014.
Article
in Zh
| WPRIM
| ID: wpr-297500
Responsible library:
WPRO
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.
Full text:
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Index:
WPRIM
Main subject:
Pharmacology
/
Physiology
/
Pulmonary Artery
/
Vasoconstriction
/
Vasodilation
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Norepinephrine
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Rats, Sprague-Dawley
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Chloride Channels
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Glycolates
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Hypoxia
Limits:
Animals
Language:
Zh
Journal:
Acta Physiologica Sinica
Year:
2014
Type:
Article