The role of sensory neurons in the antiulcer effect of centrally injected amylin in rat

Central administration of amylin (2.2 mug/rat, i.c.v.) reduces (from a mini mum of 67% to 83%) indomethacin (Indo, 20 mg Kg(-1), orally) induced ulcers in rats. The anti-ulcer effect of the peptide is not removed by the admini stration of prokinetic drugs like domperidone or neostigmine but it is redu ced by 35% in rats treated with capsaicin or with the CGRP antagonist, CGRP (8-37). These data indicate that amylin gastroprotection involves capsaicin -sensitive nerve fiber leading to CGRP-dependent gastric vasodilatory effec t. Additional mechanisms could involve noradrenergic alpha (2) receptors as the peptide gastroprotective activity is reduced from 67% to 20% by the al pha (2) antagonist yohimbine. (C) 2000 Elsevier Science Inc, All rights res erved.