目的　探索P物质对牛蛙背根神经节神经元γ -氨基丁酸激活电流抑制的机制或途径。方法　实验采用的方法是全细胞膜片钳技术 ,实验材料为急性分离的牛蛙背根神经节神经元。结果　P物质在牛蛙背根神经节神经元能引起一缓慢的内向电流 ;并且P物质能明显抑制牛蛙背根神经节神经元γ -氨基丁酸激活电流 ;蛋白激酶C的抑制剂H - 7(5 0ЧM)能阻断此抑制作用。结论　P物质可能通过蛋白激酶C抑制γ -氨基丁酸激活电流 Objective To explore the mechanism or pathway of substance P on the inhibition of γ - aminobutyric acid (GABA) activated current in dorsal root ganglion neurons of Methods The whole cell patch clamp technique was used in the experiment. The experimental materials were acutely isolated bullfrog dorsal root ganglion neurons. Results Substance P induced a slow inward current in the dorsal root ganglion neurons in the frog; and substance P inhibited the activation of γ - aminobutyric acid (GABA) in the dorsal root ganglion neurons of the frog dorsal root ganglion neurons. The inhibitor of protein kinase C, H - 7 5 0ЧM) can block this inhibitory effect. Conclusion Substance P may inhibit γ - aminobutyric acid - induced currents through protein kinase