Enteral Obestatin influences on Intestinal Contractility in Neonatal Wistar Rats ‐ in vitro Studies

Abstract

Obestatin is a 23‐amino acid peptide encoded by the ghrelin gene. Substantial amount of this peptide has been found in colostrum and milk. We have investigated the intestinal contractility of neonatal rats enterally treated with obestatin (125nmol/kg b.wt. LO; 250 nmol/kg b.wt, HO) or saline (C), (n=12 for each group), for 7 days. Duodenal and middle jejunum whole‐thickness preparations from 21 day old rats were studied in an organ bath, for isometric recording under treatment with acetylocholine (ACh), atropine and tetradotoxin (TTX). The electrical field stimulation (EFS) was performed (90 V, duration 10 sec) at three frequencies: 0.5, 5 and 50Hz with 1 min intervals. Significant decrease in amplitude was observed after treatment with higher doses of obestatin (HO) for EFS–stimulated as well as spontaneous contractile activity in both studied intestinal segments. In the lower dose (LO) obestatin treatment resulted in decrease in amplitude both for EFS ‐ stimulated as well as spontaneous contractility but only in the middle jejunum. In obestatin treated animals injection of atropine did not result in a significant decrease of amplitude of spontaneous contractility of both intestinal segments. In all experimental groups the amplitude of EFS –stimulated off‐contractions and spontaneous contractility was sensitive to treatment with TTX. These results indicate the importance of peripheral obestatin in the programming of intestinal contractility in rats during suckling period. Moreover this effect is dose dependent and independent of cholinergic pathways.Project of Polish National Science Centre 2011/03/D/NZ9/03697