Effects of hydrocortisone sodium succinate on voltage-gated sodium current in trigeminal ganglion neurons of rat.

The effects of hydrocortisone sodium succinate on voltage-gated sodium current (I(Na)) were investigated by using the patch-clamp technique in trigeminal ganglion (TG) neurons of rat. I(Na) was recorded by whole-cell patch-clamp techniques after different concentrations of hydrocortisone sodium succinate were perfused in TG neurons of rat. The results showed that hydrocortisone sodium succinate could inhibit I(Na) in concentration-dependent manner. Hydrocortisone sodium succinate 0.1, 0.3, 1, 3 μmol/l reduced I(Na) by 19.4±4.3, 26.7±3.9, 38.1±6.1, 69.6±5.4% respectively. The IC(50) was 1.58 μmol/l. This inhibitory effect occurred quickly (within 1 minute). However, hydrocortisone sodium succinate had no significant effect on the activation and inactivation courses of I(Na). It is suggested that the rapid inhibition of I(Na) in TG neurons by hydrocortisone sodium succinate is probably related to non-genomic effect. This inhibition might participate in the relaxation of pain in some emergency states.