Localization and Coexistence of Calcium‐Binding Proteins and Neuropeptides in the Vagal Ganglia of the Goat

Abstract

This study was performed to investigate the neurochemical characteristics of the vagal ganglia of the goat by immunohistochemical methods using calbindin D‐28k (CB), calretinin (CR), parvalbumin (PA), substance P (SP), calcitonin gene‐related peptide (CGRP) and galanin (GAL) antibodies. In the proximal vagal ganglia (jugular ganglia), CGRP‐ (57.1%), SP‐ (48.2%), GAL‐ (8.6%), PA‐ (8.7%), CB‐ (8.5%) and CR‐like (5.3%) immunoreactive cells were observed. In the distal vagal ganglia (nodose ganglia), CGRP‐ (40.5%), SP‐ (30.2%), CB‐ (22.0%) and CR‐like (18.1%) immunoreactive cells were present. The double immunohistochemical study showed, that in the proximal vagal ganglia, CGRP immunoreactivity was co‐localized in SP‐ (84.8%), GAL‐ (100%), CB‐ (5.6%) and CR‐ (5.7%) immunoreactive cells; SP immunoreactivity was co‐localized in the CGRP‐ (80.0%), GAL‐ (100%), CB‐ (5.3%) and CR‐ (5.6%) immunoreactive cells; GAL immunoreactivity coexisted in the CGRP‐ (4.4%) and SP‐ (19.8%) immunoreactive cells, but not in calcium‐binding proteins (CBP)‐immunoreactive cells; PA immunoreactivity was absent in the CGRP‐ and SP‐immunoreactive cells; CB and CR immunoreactivities were seen in the CGRP‐ (0.8%) and SP‐immunoreactive (0.9%) cells. On the other hand, in the distal vagal ganglia, CGRP immunoreactivity appeared in SP‐ (66.6%), CB‐ (1.0%) and CR‐ (1.2%) immunoreactive cells; SP immunoreactivities were observed in the CGRP‐ (44.1%), CB‐ (1.0%) and CR‐ (1.2%) immunoreactive cells; CB immunoreactivities were present in the CGRP‐ (0.5%) and SP‐ (0.8%) immunoreactive cells; CR immunoreactivities were contained in the CGRP‐ (0.5%) and SP‐ (0.8%) immunoreactive cells. These findings indicate that the goat is distinct from other mammalian species in the distribution and localization of neurochemical substances in the vagal ganglia, and suggest that these differences may be related to physiological characteristics, particular those of the ruminant digestive system.