Role of K~+ channels in attenuation of pulmonary vasoreactivity following chronic hypobaric hypoxia in rats / 中国病理生理杂志

ABSTRACT

AIM and METHODS: To determine the role of different K +-channels in attenuation of vasoreactivity of intrapulminary artery rings induced by chronic hypoxia. RESULTS: ①Acute hypoxia-induced pulmonary vasoconstriction(HPV) could be significantly attenuated by chronic hypobaric hypoxia for 15 days and for 30 days. ②HPV could be significantly potentiated by ATP-sensitive K +-channel (K ATP ) blocker or Ca 2+ -activated K +-channel (K Ca )blocker, and the potentiated scope in chronic hypoxic group was much higher than that observed in control group. ③ Delayed rectifier K +-channel (K DR )blocker showed no effect on HPV in both control group and chronic hypoxic group.CONCLUSIONS: Both K ATP and K Ca play an important modulating role in HPV and it's potentiation may be a critical mechanism for the attenuated vasoreactivity to acute hypoxia; following chronic hypobaric hypoxia.