腺苷及异丙基肾上腺素对工作心肌细胞的电生理影响

Electrophysiologic Effects of Adenosine and Isoproterenol on Atrial and Ventricular Myocytes in Guinea Pig Heart

运用标准玻璃微电极技术，观察腺苷（Ado）及异两基肾上腺素（Iso）对豚鼠心房、心室肌细胞动作电位（AP）的影响及其相互作用。结果表明，Ado可缩短心房肌细胞动作电位时程（APD），对其膜静息电位（RP）、动作电位幅度（APA）及零相最大去极化速率（Vmax）无影响；对心室肌细胞，即使较高浓度Ado亦无明显影响。Iso可使心房、心室肌细胞APD延长，Ado可消除Iso的电生理作用。Ado的这些电生理作用均可被选择性腺苷A1受体拮抗体DPCPX所拮抗。

Using microelectorde technique, we studied the electrophysiologic effects of adenosine (Ado) andisoproterenol' (Iso). The results indicated:To atrial myocytes, Ado can shorten APD but has no effects on RP'APA and Vmax. To ventricular myocytes, Ado has no obvious action. Iso can prolong APD of atrial and ventricu-lar myocytes. Ado can e1iminate the actions of Iso. These actions of Ado can be antagonized by DPCPX. These re-sults suggest that through A1 receptor mediation, Ado can antagonize the effects of Iso.