Neuropeptides in the intestine of two teleost species ( Oreochromis mossambicus, Carassius auratus ): Localization and electrophysiological effects on the epithelium

摘要: The presence of bioactive peptides in the gut and their possible electrophysiological effects on intestinal epithelium were studied two teleost species, tilapia (Oreochromis mossambicus) goldfish (Carassius auratus). Vasoactive polypeptide-like immunoreactive nerve fibres found beneath both species. Galanin-, metenkephalin-and calcitonin gene-related peptide-like exclusively mucosa tilapia. Both species had vasoactive polypeptide-, enkephalin- or neuropeptide Y-like endocrine cells; cells additionally Somatostatin- dopamine-β-hydroxylase-like immunoreactivities not observed. Nerve cell bodies myenteric plexus showed immunoreactivity for peptide-, galanin-like peptide. Enkephalin-like present only. None a pronounced electrogenic effect. However, peptide added to stripped tilapia, reduced ion selectivity, addition galanin increased selectivity. In intestine, without Enkephalin counteracted serotonin-induced reduction selectivity epithelium, but no effect epithelium. polypeptide Y induced an increase Somatostatin epithelial either Tetrodotoxin did inhibit studied. changes suggest that enterocytes may be under regulatory control these peptides.