INCREASED SYNAPTIC AVAILABILITY OF NOREPINEPHRINE FOLLOWING DESIPRAMINE IS NOT ESSENTIAL FOR INCREASES IN GR MESSENGER-RNA - SHORT COMMUNICATION

Male Sprague-Dawley rats were treated for 7 days with the norepinephri ne (NE) uptake inhibitors desipramine (DMI) or (+)-oxaprotiline or the inactive (-)-enantiomer of oxaprotiline. DMI, as previously reported, significantly increased hippocampal glucocorticoid receptor (GR) mRNA while the equipotent NE uptake inhibitor (+)-oxaprotiline like the in active (-)-oxaprotiline did not alter hippocampal levels of GR mRNA. T he results indicate that an increase in the synaptic availability of N E as a consequence of uptake inhibition is not responsible for the act ion of DMI on GR gene expression.