[The ionic mechanism of hyperpolarization induced by glucocorticoid and its modulatory effects in mammalian neurons].

This is the first report to investigate the rapid hyperpolarization by glucocorticoid in coeliac ganglion neurons of guinea pig in vitro. Hydrocortisone 21-hemisuccinate (F-suc) caused rapidly hyperpolarization in neurons; hyperpolarization persisted after the elimination of synaptic inputs and after suppression of protein synthesis with actinomycin D; F-suc also induced hyperpolarization when picrotoxin or Ca(2+)-free in perfusion solution; TEA and 4-AP can inhibit the hyperpolarization of F-suc. These results provided evidence that F-suc's hyperpolarization may be mediated by potassium channel in the membrane. Also F-suc suppressed the discharges of neurons; and modulated rapidly effects of neurons to excitatory or inhibitory amino acids (P < 0.05).