The Effect Of No On The Membrane Of Dorsal Root Ganglion Neurons In Rat

Objective:In this study,we taked dorsal root ganglion (DRG)of rats as a model to observe the role of NO (nitric oxide) and its related ionic mechanisms in DRG neurons, and explored the function of NO in pain transmission process in order to provide new way for clinical treatment of pain .Methods:1, In freshly isolated rat DRG samples, using intracellular recording technique,we perfused sodium nitroprusside(NO donor) to observe the role of NO in DRG neurons.2, When perfusing SNP and recording membrane potential, we generated the hyperpolarized square wave (wave width 400 ms, intensity 1.0 nA, frequency 0.25 Hz) through the same microelectrode, and calculated the value change in membrane conductance according to the shift of membrane electrotonic potential.3, Channel blockers and non-sodium BSS were used to observe the ionic mechanisms of NO.Results: 1, Most of neurons were sensitive to sodium nitroprusside (79/102, 77.45%) and hyperpolarized by sodium nitroprusside (10 ~ 100 mmol / L) in a concentration-dependent manner. EC50 was 30.3 mmol/L. The rest were no response. The membrane conductance of neurons increased from 21.06±1.94 nS to 23.08±0.92 nS when perfusing sodium nitroprusside (100 mmol / L); 2, 1 mmol / L L-NAME (non-selective nitric oxide synthase inhibitor), 0.1 mmol / L CdCl2 (non-selective calcium channel blocker), non-sodium BSS had no effect on the SNP-induced hyperpolarization which conversely could be markedly inhibited by 10 mmol / L Tetraethylammonium iodide (non-selective potassium channel blocker).Conclusions: 1, Sodium nitroprusside (NO donor) can cause concentration-dependent hyperpolarization in rat DRG neurons;2, The concentration-dependent hyperpolarization of sodium nitroprusside were mediated by potassium conductance.