Depletion of gastrin-releasing peptide (GRP) from nerves in the gastric body of rats with experimental ulcers. An immunohistochemical study.

A predominant population of mucosal nerves in the mammalian gastric body has been known to contain large amounts of gastrin-releasing peptide (GRP). The present immunohistochemical study demonstrates the depletion of GRP immunoreactivity from nerves in the oxyntic mucosa of rats with ulcers induced by restraint plus water immersion. Depletion of GRP occurred in a major part of the nerves after 3 h exposure to the stress, and after 6 h exposure only a few nerve fibers could be recognized. In contrast, GRP fibers in the pyloric mucosa did not decrease significantly in number in any of the stressed rats. Since the depletion of GRP immunoreactivity preceded mucosal erosion in the gastric body, the possibility is proposed that GRP released from the nerves may be related to stress-related ulceration in the stomach.