Binding Sites for VIP in the Reorganizing Mucosa of the Irradiated Bowel^a

Abstract

Rats were given radiotherapy (total dose 30 Gy) over the abdomen. Seven days later specimens of the duodenum were prepared for in vitro receptor autoradiography using the radioligand [125I]VIP. The autoradiograms were quantitatively analyzed using a computer system. Histological examination revealed that a very marked reorganization of the mucosa had occurred in response to irradiation. Using receptor autoradiography, we found [125I]VIP-specific binding sites in the reorganizing mucosa, except where denudation had occurred. Such binding sites also occurred in the smooth muscle layer of the duodenal wall. The observations suggest that VIP has profound effects in radiation-induced enteropathy.

Decrease in Binding for the Neuropeptide VIP in Response to Marked Inflammation of the Mucosa in Ulcerative Colitis

“…Furthermore, in parallel to low levels of VIP binding, there was also a comparatively low level of VIP innervation in these areas. In comparison, in regions of rat duodenal mucosa showing very marked mucosal denudation in response to irradiation, no clear evidences of VIP‐binding sites were observable 11 . Another finding in the present study was the observation that the VIP‐binding sites in general were most clearly detected in the superficial part of the mucosa.…”

“…In comparison, in regions of rat duodenal mucosa showing very marked mucosal denudation in response to irradiation, no clear evidences of VIP-binding sites were observable. 11 Another finding in the present study was the observation that the VIP-binding sites in general were most clearly detected in the superficial part of the mucosa. Similar observations have been made in previous studies on the human colon.…”