COLOCALIZATION OF NADPH-DIAPHORASE WITH NITRIC-OXIDE SYNTHASE AND VASOACTIVE INTESTINAL POLYPEPTIDE IN NEWBORN PANCREATIC NEURONS

Numerous NADPH-diaphorase positive neurons were localised in the pancr eatic ganglia cultured from newborn guinea pigs. Most of these ganglia were found in the head region of the pancreas. A majority of the labe lled neurons occurred in groups, although solitary neurons were also p resent. NADPH-diaphorase labelling was localised mainly in the cell cy toplasm and its processes, but not within the nucleus. There were more nitric oxide synthase (NOS)-immunoreactive neurons in culture as comp ared with those positive for NADPH-diaphorase. NADPH-diaphorase activi ty has been colocalised with NOS and vasoactive intestinal polypeptide (VIP) in a subset of neurons in culture. Colocalisation of NADPH-diap horase with NOS and VIP in cultured neurons was not restricted to the cell body but also to the proximal and distal processes. Some of these labelled processes made contacts with exocrine acinar and endocrine c ells. It is concluded that neuronal nitric oxide (NO) may be influenci ng the secretory roles of the pancreas, thereby participating in homeo stasis.