Changes and Significance of Tetrodotoxin-resistant Sodium Channels Current of Dorsal Root Ganglion Nociceptive Neurons in Rats with Diabetes

Objective To investigate the characteristic changes of tetrodotoxin-resistant( TTX-R) sodium channels of dorsal root ganglion neuron( DRG) in rats with diabetic neuropathological pain( DNP),so as to explore the possible mechanism of hyperalgesia induced with DNP. Methods The DNP model was prepared in 8 SD rats with intraperitoneal injection of streptozotocin. The neuron was isolated from L5 ~ 6DRG with adherent digestive method and cultured in vitro. The electric current was recorded with electrophysiological whole-cell patch clamp technique. Another 8 SD rats with same month age were selected as control group. Results The electric current density of TTX-R INaof minor diameter DRG in DNP rats was higher than that of control group. The activated curve was moved 3. 9 mV to hyperpolarzation compared with control group,the ratio of repetitive discharge neurons in DNP group was significantly increased than that of control group( P 0. 05). Conclusion The electric current change of minor diameter DRG may play an important role in the hyperalgesia of rats with DNP.