Prodynorphin-derived peptide expression in primate cortex and striatum

Abstract

The distributions of four prodynorphin-derived peptides, dynorphin A (1-17), dynorphin A (1-8), dynorphin B, and [alpha]-neo-endorphin were determined in 10 cortical regions and the striatum of the old world monkey (Macaca nemestrina). [alpha]-neo-endorphin was the most abundant peptide in both cortex and striatum. The concentrations of all four peptides were significantly greater in the striatum compared to the cortex. In general, concentrations of each peptide tended to be higher in allocortex than in neocortex. Possible inter- and intradomain processing differences, as estimated by ratios of these peptides, did not vary within cortex, but the intradomain peptide ratio, dyn A (1-17)/dyn A (1-8), was significantly greater in cortex than in striatum. These results indicate that prodynorphin is, in some ways, uniquely processed in the primate. Particularly unusual is the relatively low abundance of prodynorphin-derived products in the cortex, in the face of moderately high levels of kappa opiate receptor expression.