Co-expression of Cholecystokinin and Neuropeptide Y by Glutamatergic Stimulation in PC12 Cells

Abstract

Co-expression of cholecystokinin (CCK) and neuropeptide Y (NPY) by glutamatergic stimulation was examined by double stained immnocytochemistry in the rat PC12 cells. Co-expression of CCK and NPY was inducible by glutamate and N-methyl-D-aspartate (NMDA), but not by kainic acid. Pretreatment of the cells with non-competitive NMDA antagonist, MK-801 (10 µM), and competitive NMDA antagonist, AP5 (10 µM), slightly suppressed the elevated levels of glutamate-induced CCK and NPY immunoreactivity, but markedly inhibited those of NMDA-induced CCK and NPY immunoreactivity. These results suggest that CCK and NPY expressions are mainly regulated through the NMDA-induced signaling pathways, and both molecules could be co-expressed via NMDA receptors upon glutamatergic neuroexcitation at the synaptic junction.