【摘要】 目的观察金雀异黄素(GST)对大鼠肠系膜动脉平滑肌细胞(MASMC)钾电流(IK)的影响。方法采用急性酶分离法获得SD大鼠单个MASMC,应用全细胞膜片钳记录方法,研究GST对IK以及膜电位的影响。结果 (1)GST(100μmol/L)可以快速可逆的抑制IK(P<0.05),tyrphostin25(10μmol/L)也可抑制IK(P<0.05),其作用与GST类似,而Daidzein(100μmol/L)对IK没有显著影响(P>0.05)。(2)在电极内液不含ATP的条件下,GST(100μmol/L)和tyrphostin25(10μmol/L)对IK的抑制没有统计学意义(P>0.05)。(3)GST能浓度依赖性地去极化膜电位(P<0.05),而且此作用是可逆的。Daidzein(100μmol/L)、tyrophostin25(10μmol/L)则对膜电位没有明显影响(P>0.05)。结论 GST可以快速可逆的抑制IK,使膜电位去极化,其作用与酪氨酸磷酸化相关。更多还原

【Abstract】 Objective To observe the effects of genistein on potassium currents of smooth muscle cells of mesenteric arteries(MASMC) in rats.Methods Single MASMC was obtained with acute enzyme dispersing method.The whole-cell patch-clamp technique was used to measure the membrane potential and potassium currents affected by genistein.Results(1) Genistein(100μmol/L)rapidly and reversibly inhibited potassium currents(P<0.05),which were insensitive to daidzein(100μmol/L)(P>0.05),whereas tyrphostin25(10μmol/L) had similar inhibitory effects as genistein(P<0.05).(2) The inhibition of potassium currents induced by genistein and tyrphostin25 was statistically insignificant(P>0.05) without ATP in the pipette.(3)Genistein(100μmol/L) reversibly and concentration-dependently depolarized the membrane potential of MASMC(P<0.05).Neither Daidzein(100μmol/L) nor tyrophostin25(10μmol/L) had any effects on membrane potential(P>0.05).Conclusions The present results suggest that genistein can rapidly and reversibly inhibit potassium currents and depolarize MASMC,which may be correlated with protein tyrosine phosphorylation.更多还原