The influence of different sub-type delta opioid receptors in nerve growthfactor-induced neuronal differentiation in rat pheochromocytoma PC12 cell

The impairment of neuronal differentiation for long-term opioid drug-expose d infants is a serious problem and there are several speculated mechanisms. We have previously reported that altering the endogenous delta opioid rece ptor by long-term interaction with its antagonist augmented the nerve growt h factor (NGF)-induced neuronal differentiation of rat pheochromocytoma PC1 2 cells. In this study using subtype-specific antagonist, we present data s howing further that type 2 delta opioid receptor (delta (2)-DOR) is the rec eptor on the PC12 cells participating in the progression of neuronal differ entiation upon NGF-stimulation. Unlike the delta (2)-DOR, alteration of typ e 1 DOR (delta (1)-DOR) activity by delta (1)-DOR-specific antagonist appea red to be toxic for the PC12 cells. The different influence of the subtypes of delta opioid receptors in the neuronal differentiation of the PC12 cell s suggests that each subtype of opioid receptor may trigger different biolo gical activities in vivo. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.