Amylin is a peptide that displays 50% homology with calcitonin gene-related peptide (CGRP). Amylin is colocalized with somatostatin in endocrine cells of the gastric fundus. In isolated mouse stomach. amylin caused a concentration-dependent decrease in acid secretion. In rat fundic segments. amylin and CGRP each caused a concentration-dependent increase in somatostatin and a decrease in histamine secretion.