Protective effect of apocynin on oxidative damage of inward rectifier potassium current in rabbit left atrial myocytes

  AIM  To study the protective effect of apocynin (APO) on oxidative stress damage of inward rectifier potassium current (I_K1) in rabbit left atrial myocytes.

  METHODS  We made the model of oxidative stress by low level H₂O₂ (50 μmol/L). The whole cell patch clamp technique was used to study the protective effect of APO on IK1 and action potential duration (APD) under oxidative stress injury. Real-time qPCR and Western blot were used to detect the expression of KCNJ2 at mRNA and Kir2.1 protein levels.

  RESULTS  APO restored the peak current decreased by H₂O₂. APO also recovered the shortened resting membrane potential (RMP) and APD₉₀ caused by H₂O₂. Compared with those in H₂O₂ group, the expression of KCNJ2 mRNA and the protein levels of Kir2.1 were increased (P<0.05), which could be recovered by APO+H₂O₂.

  CONCLUSION  APO has some protective effect on I_K1 in left rabbit atrial myocytes.