Influence of acute hypoxia on current of voltage-gated potassium channel in pulmonary artery smooth muscle cells of rats / 心血管康复医学杂志

ABSTRACT

Objective: To study influence of acute hypoxia on the current of voltage-gated potassium channel (IK) in pulmonary artery smooth muscle cells (PASMC) of rats. Methods: A total of 20 male SD rats were randomly and equally divided into normoxic control group and acute hypoxia group. The rats in acute hypoxia group were kept in hypoxic chamber for 8 h before experiment. Whole cell patch-clamp technique was used to record IK in PASMC. Results: Acute hypoxia significantly decreased the IK density in PASMC of rats. During -60mV to -10mV of resting membrane potential（RMP）, acute hypoxia did not significantly decrease peak IK density in PASMC of rats, P>0.05; At 0 mV, acute hypoxia significantly decreased the peak IK density in PASMC [from（38.1 ± 5.2） pA / pF decreased to（9.82 ± 2.1） pA / pF ,P<0.05], then along with RMP increase in PASMC, the decreasing amplitude of peak IK density in PASMC gradually increased（P<0.05）; From + 30 mV to+ 60 mV, the decreasing amplitude of peak IK density in PASMC further significantly increased（P<0.01）; At + 60 mV the peak IK density decreased from（38.1 ± 5.2） pA / pF to（9.82 ± 2.1） pA / pF , and the decreasing amplitude reached (46.8±3.3)%. Conclusion: Acute hypoxia can decrease Kv current in PASMC of rats, leading to hypoxic pulmonary vasoconstriction.