Differential gene expression of dopamine D-2 receptor subtypes in rat chromaffin cells and sympathetic neurons in culture

Chromaffin cells and sympathetic neurons arise from a common bipotential pr ogenitor which, if exposed to nerve growth factor (NGF), matures into a sym pathetic neuron, but if exposed to glucocorticoids (GCs), differentiates in to a mature chromaffin cell. Pharmacological evidence indicates that, in ad renal medulla and sympathetic neurons, dopamine (DA) receptors belonging to the D-2 family inhibit catecholamine secretion. The molecular characteriza tion of these receptors, however. is not been yet described. Our data sugge st that bipotential cells obtained from newborn rat adrenal medulla express both isoforms of the D-2 receptor, while D-3 receptor and D-4 receptor mes senger RNAs (mRNAs) are not present. GC-mediated maturation induces the exp ression of D-4 receptors, without modification of D-2 isoforms. Sympathetic neurons differentiated in vitro selectively express the D-2short mRNA. Tak en together, present results suggest that NGF and GCs play a role in regula ting D-2 family receptor expression in neural crest-derived cells. NeuroRep ort 11:2467-2471 (C) 2000 Lippincott Williams & Wilkins.