Effects of dexamethasone on [3H]choline uptake by rat forebrain synaptosomes.

Dexamethasone (3-300 mumol/l) did not affect uptake of choline (1 mumol/l) by rat forebrain isolated nerve terminals (crude synaptosomal fraction). At concentrations which have been shown to increase choline uptake by rat superior cervical ganglion, dexamethasone had no effect on synaptosomal choline uptake at choline concentrations between 0.1 and 30 mumol/l, nor on choline uptake which had been partially inhibited either by hemicholinium-3 (0.1 mumol/l) or by reducing the NaCl concentration (0-140 mmol/l).