Adrenomedullin promotes epithelial restitution of rat and human gastric mucosa in vitro

We have investigated the effect of adrenomedullin (AM) on restitution of mu cosal integrity following damage in rat and human gastric mucosa, measuring the potential difference (PD) on a mucosal strip mounted on an Ussing cham ber. Mucosal damage was induced by 0.5, 1.0, and 2.0 M NaCl solution, and i t caused an immediate and significant decrease in PD. In the rat AM group, PD recovered significantly more than in control group at 120 min after expo sure to 0.5 M (p < 0.01) and 1.0 M (p < 0.05) NaCl solution. In the human A M group, PD completely recovered at 120 min after exposure to 0.5 M (p < 0. 05) NaCl solution. In rat mucosa damaged by 0.5 M NaCl solution, the effect was inhibited by human (h)-CGRP(8-37) and there was no significant differe nce between the h-CGRP(8-37) group and control group. On immunohistochemica l examination of rat gastric mucosa, AM was detected within the chief cell. AM probably promotes epithelial restitution primarily through the CORP rec eptor, but it does not ameliorate more severe damage of gastric mucosa in v itro. (C) 1999 by Elsevier Science Inc.