NISCAIR Online Periodicals Repository

NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR)  >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Experimental Biology (IJEB) >
IJEB Vol.48 [2010] >
IJEB Vol.48(02) [February 2010] >


Title: Characteristics of phase 3-like activity and rebound excitation triggered by hexamethonium and atropine administration in the ovine small bowel
Authors: RomaƄski, K W
Keywords: Anticholinergic drugs
Duodenum
Jejunum
Migrating myoelectric complex
Phase 3-like activity
Rebound excitation
Sheep
Issue Date: Feb-2010
Publisher: CSIR
Abstract: Administration of hexamethonium (Hx) and atropine inhibits myoelectric and motor activity and then evokes a stimulatory effect called rebound excitation (RE) in the ovine small bowel. RE has not been precisely characterized so far and it is possible that it is composed of different types of motility. This study was thus devoted to characterizing these excitatory changes in the myoelectric and motor activity of the small bowel, particularly in the duodenum in conscious sheep. These alterations occurred in response to different intravenous doses of Hx and atropine administered alone or in combinations during various phases of the migrating myoelectric or motor complex (MMC) in the fasted and non-fasted sheep. Initially two basic types of excitatory response to the cholinergic blockade were found. In the course of chronic experiments different doses of Hx and atropine evoked phase 3-like activity (unorganized phase 3 of the MMC or its fragments) alternating with the less regular RE and the duration of these changes was related to the drug dose. In the non-fasted sheep these changes were less pronounced than in the fasted animals. When the drug was given during phase 1 of the MMC, RE did not occur or was greatly reduced. Administration of Hx and atropine in the course of phase 2a and phase 2b of the MMC produced roughly similar effects. Hx triggered stronger phase 3-like activity and RE than atropine. Combinations of Hx and atropine induced an additive effect, more evident in the fasted animals. These actions of Hx and atropine, thus, appear to involve at least partly the same intramural pathways. It is concluded that Hx and atropine evoke phase 3-like activity alternating with RE as the secondary stimulatory response in conscious sheep and both these types of the intestinal motility represent two distinct motility patterns.
Page(s): 124-132
ISSN: 0975-1009 (Online); 0019-5189 (Print)
Source:IJEB Vol.48(02) [February 2010]

Files in This Item:

File Description SizeFormat
IJEB 48(2) 124-132.pdf447.77 kBAdobe PDFView/Open
 Current Page Visits: 576 
Recommend this item

 

National Knowledge Resources Consortium |  NISCAIR Website |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2012 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 639879 since 06-Feb-2009  Last updated on 15-Dec-2014Webmaster: nopr@niscair.res.in