[Effects of intracellular osmolality changes on the voltage-gated sodium channels currents of trigeminal ganglion neuron].

Objective: To evaluate the biomechanical effects of intracellular changes on the voltage-gated sodium channels (VGSCs) on trigeminal ganglion neuron (TRGN).

Methods: TRGN cells were acutely isolated from the neonatal SD rats. The voltage-dependent currents of the VGSCs on these neurons were elicited and analyzed by whole-cell patch-clamp recordings and the intracellular anisotonicity stimuli was established by adjusting the content of pipette solution. The effects of hypo-(260 mOsm) and hypertonic (350 mOsm) osmolarity on the activation and inactivation kinetics of VGSCs on TRGN were evaluated, compared with the normal intracellular environment.

Results: The results demonstrated that intracellular hypotonic stimuli could influence both the activation and inactivation characteristics of VGSCs currents, including the membrane potential at half inactivation (V0.5) of the G-V and inactivation curves had obvious statistics significance (P<0.05) between hypotonicity (260mOsm) and isotonicity (306mOsm). However, only inactivation properties changed under intracellular hypertonic effects, including inactivation rate and k value.

Conclusion: It suggests that the kinetics of VGSCs on TRGN can be modulated both by intracellular hypo- and hypertonic with different characteristics.