Effect of BQ123 on the voltage-gated K~+ current of pulmonary artery smooth muscle cells of rats exposed to chronic hypoxia / 中国病理生理杂志

ABSTRACT

AIM: To study the effect of BQ123 on voltage-gated K+ current in pulmonary artery smooth muscle cells(PASMCs) from chronic hypoxic rats.METHODS: Twelve age and body weight matched Wistar rats were randomly divided into control and chronic hypoxic group.Single PASMCs were obtained with acute enzyme(collagnaseⅠ plus papain) dispersing method.Using the whole cell patch-clamp technique in freshly isolated PASMCs from normorxic and hypoxic rats,the effects of ET-1 and BQ123,a selective ETA receptor antagonist,on voltage-gated K+ current were recorded.RESULTS:(1) ET-1(10-8 mol?L-1) caused inhibition of K+ current in PASMCs from normoxic and hypoxic rats.The effect of ET-1 on K+ current in PASMCs from hypoxic rats was greater than that from normoxic rats [+50 mV,percent inhibition were(71.04?6.58)% and(60.21?5.32)%,respectively,P0.05,n=5),nor ETA receptor blockade had change of ET-1 mediated IKV inhibition.(3) In chronic hypoxic PASMCs,BQ123 significantly reduced the effect of ET-1 mediated IKV inhibition,from(28.49?6.69) pA/pF to(74.19?9.74) pA/pF at +50 mV(P