Facilitation of Chronic Intermittent Hypobaric Hypoxia on Carotid Sinus Baroreflex in Anesthetized Rats

Lu Gao ； Yue Guan ； Fang Cui ； Yi-xian Liu ； Zhao-Nian Zhou ； Yi Zhang

《The Chinese Journal of Physiology》 55卷1期 (2012/02) Pp. 62-70

https://doi.org/10.4077/CJP.2012.AMM076

並列摘要

Our previous study showed that chronic intermittent hypobaric hypoxia (CIHH) could prevent decreases in systemic arterial blood pressure (SABP) during acute hypoxia. However, the mechanism was not clear. The purpose of the present study was to observe whether the carotid sinus baroreflex (CSB) was involved in the antagonizing effect of CIHH on SABP decrease induced by acute hypoxia and to explore the underlying mechanism using perfusion technique in rat isolated carotid sinus area. After 14-day and 28-day CIHH exposure, the CSB in rats was enhanced markedly, manifesting as increases in PS and RD, and decreases in TP and SP. This facilitation of CSB was partly abolished by Glibenclamide (Gli, 10 μM), a K(subscript ATP) channel blocker, but was not influenced by L-NAME (100 μM), a nitric oxide synthase (NOS) inhibitor. The results of the study suggested that CIHH facilitated CSB through opening the K(subscript ATP) channels in carotid sinus of anesthetic rats and might be one of mechanisms of CIHH keeping SABP homeostasis during acute hypoxia.

並列關鍵字

chronic intermittent hypobaric hypoxia ； carotid sinus ； baroreflex ； mean arterial pressure ； K(subscript ATP) channel ； rat

參考文獻

Akrouh, A.,Halcomb, S.E.,Nichols, C.G.,Sala-Rabanal, M.(2009).Molecular biology of KATP channels and implications for health and disease.IUBMB Life.61,971-978.

Béguin, P.C.,Joyeux-Faure, M.,Godin-Ribuot, D.,Lévy, P.,Ribuot, C.(2005).Acute intermittent hypoxia improves rat myocardium tolerance to ischemia.J. Appl. Physiol..99,1064-1069.

Behm, R.,Honig, A.,Griethe, M.,Schmidt, M.,Schneider, P.(1984).Sustained suppression of voluntary sodium intake of spontaneously hypertensive rats (SHR) in hypobaric hypoxia.Biomed. Biochem. Acta.43,975-985.

Fu, Q.,Townsend, N.E.,Shiller, S.M.,Martini, E.R.,Okazaki, K.,Shibata, S.,Truijens, M.J.,Rodríguez, F.A.,Gore, C.J.,Stray-Gundersen, J.,Levine,B. D.(2007).Intermittent hypobaric hypoxia exposure does not cause sustained alterations in autonomic control of blood pressure in young athletes.Am. J. Physiol. Regul. Integr. Comp. Physiol..292,R1977-R1984.

Gu, H.,Lin, M.,Liu, J.,Gozal, D.,Scrogin, K.E.,Wurster, R.,Chapleau, M.W.,Ma, X.,Cheng, Z.J.(2007).Selective impairment of central mediation of baroreflex in anesthetized young adult Fischer 344 rats after chronic intermittent hypoxia.Am. J. Physiol. Heart Circ. Physiol..293,H2809-H2818.