title: Age-dependent effect of obestatin on intestinal contractility in Wistar rats.
abstract: Obestatin is a 23-amino acid peptide encoded by the ghrelin gene. We have investigated the effect of obestatin on intestinal contractility in rats ranging from the suckling period till adolescence. Duodenal and middle jejunum whole-thickness preparations from neonatal and adult rats were studied in an organ bath, for isometric recording under treatment with obestatin (1μmolL(-1)) in the presence of acetylocholine (ACh), atropine and tetradotoxin (TTX). Both the EFS and ACh-stimulated contractile response, as well as spontaneous contractile activity is age-dependent and specific for the segment of jejunum. Except for the middle jejunum of 7day old rats, treatment with obestatin caused a significant TTX-sensitive increase in the amplitude of EFS-stimulated off-contraction of both intestinal segments studied. Following injection of obestatin, the amplitude of spontaneous contraction in the duodenum increased in 7day old rats. In the middle jejunum, treatment with obestatin significantly increased both the amplitude and frequency of spontaneous contraction in rats till the 28th day of life, whereas in adult rats the observed effect of obestatin was the opposite (P<0.001 and P<0.0001, respectively). The effects of treatment with obestatin on stimulation with increasing doses of ACh were only observed in the preparations from suckling rats. ACh-stimulated contractility in the duodenum was decreased while in the middle jejunum the observed effect was opposite. These results indicate the importance of peripheral obestatin in the cholinergic control of intestinal contractility in both neonatal and adult rats.
authors.affiliation: Department of Endocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland. Electronic address: m.slupecka@ifzz.pan.pl.
authors.forename: M
authors.initials: M
authors.lastname: Słupecka
authors.affiliation: Department of Biology, Lund University, Lund, Sweden; Department of Medical Biology, Institute of Agricultural Medicine, Lublin, Poland.
authors.forename: S G
authors.initials: SG
authors.lastname: Pierzynowski
authors.affiliation: Laboratory of Physiology, Institute for Environmental Sciences & Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kuwahara
authors.affiliation: Department of Bioorganic Chemistry, Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Kato
authors.affiliation: Department of Endocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Woliński
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000375:Aging / Q000502:physiology*; D000818:Animals; D004386:Duodenum / Q000187:drug effects / Q000502:physiology; D004558:Electric Stimulation; D054439:Ghrelin / Q000494:pharmacology*; D066298:In Vitro Techniques; D007422:Intestines / Q000187:drug effects / Q000502:physiology*; D007583:Jejunum / Q000187:drug effects / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D017208:Rats, Wistar
chemical_list: D054439:Ghrelin; D000109:Acetylcholine
keywords: Contractility; Intestine; Neonates; Obestatin