<b>Immunoreactive VIP (vasoactive intestinal polypeptide) in canine intestinal mucosa and </b><b>muscle </b>

Abstract

VIP-like immunoreactivities in the canine intestinal mucosa and muscle were examined by using three kinds of region-specific anti-porcine VIP sera. In any assay systems, VIP-like immunoreactivity in the extract of the muscle layer was found to be 6.5-6.7 times as high as that in the mucosa. The elution profiles on gelfiltration of the immunoreactivity in the mucosa extract differed depending on the assay system used. Particularly in the system with the carboxyl-terminal specific antiserum R-505, there were observed several components with VIP-like immunoreactivity. Immunostaining with one of the antisera revealed not only an abundance of VIP-immunoreactive nerves in the colon muscle layer, but also the endocrine-like cells of the colon. Although molecular features ofthe VIP-like immunoreactivities in the mucosa remain to be clarified, the present results indicate distinct difference in quantity and composition between the VIP-like immunoreactivities in the extracts of canine colon mucosa and the remaining muscle.