Objective To investigate what effects BmKAS 1 (a polypeptide purified from the Chinese scorpion Buthus martensi Karsch [BmK] and named as BmK activator of skeletal muscle ryanodine receptor) and its upstream mixture BmK1 3 2 have on Na + channels in dorsal root ganglion (DRG) small diameter neurons Methods The whole cell patch clamp technique was used to investigate the effects of BmKAS 1 and BmK1 3 2 on Na + current in rat small diameter DRG neurons Results About 50% peak Na + current was suppressed by 10?μg/ml of BmK1 3 2 1 62?μg/ml of BmKAS 1 also blocked 50% peak Na + current, and there was an obvious dose dependent relationship Conclusion Both BmK1 3 2 and BmKAS 1 have a blocking effect on Na + channels, and this may one of the mechanisms for the analgetic effect of BmK1 3 2 and BmKAS 1
