Neuropeptides in the porcine coeliac-superior mesenteric ganglion.

The occurrence and distribution of tyrosine hydroxylase, neuropeptide Y, somatostatin, Met5-enkephalin-Arg6-Gly7-Leu8, vasoactive intestinal polypeptide, substance P, calcitonin gene-related peptide, bombesin gastrin releasing peptide and galanin were immunohistochemically studied in the perikarya and nerve fibres of the porcine coeliac-superior mesenteric ganglion of untreated juvenile pigs. Subpopulations of neurons containing immunoreactivities to tyrosine hydroxylase, neuropeptide Y, Met5-enkephalin-Arg6-Gly7-Leu8, somatostatin, vasoactive intestinal polypeptide and galanin were disclosed in the studied ganglion, whereas principal ganglionic cells were non-immunoreactive for other investigated peptides. Double-immunofluorescence and analysis of consecutive sections revealed a partial colocalization of tyrosine hydroxylase and neuropeptide Y, Met5-enkephalin-Arg6-Gly7-Leu8 and somatostatin, whereas immunoreactivity to vasoactive intestinal polypeptide and/or to neuropeptide Y was found in non-noradrenergic neurons in this ganglion. All of neuropeptides studied were found in nerve fibres in this ganglion. The results of this study were compared with those of previous studies performed on other species.