Peptidergic and adrenergic innervation of pancreatic ganglia.

Immunocytochemical studies have revealed the presence of nerves showing vasoactive intestinal polypeptide (VIP), substance P (SP), enkephalin, and COOH-terminal gastrin/CCK immunoreactivity in the feline pancreas. Most peptide-containing nerve fibers are detected in ganglia of the pancreas, where they appear to innervate the ganglionic cell bodies. Adrenergic nerve fibers are also detected in pancreatic ganglia. The peptidergic and adrenergic nerves are only occasionally detected in the vicinity of pancreatic exocrine cells. VIP, SP, enkephalin, and gastrin/CCK exert strong effects on the secretory functions of the pancreas. Our results suggest that that ganglia may represent an important physiological site of action for these peptides and for norepinephrine.