Basic Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pharmacol Ther. Aug 6, 2016; 7(3): 416-427
Published online Aug 6, 2016. doi: 10.4292/wjgpt.v7.i3.416
Effects of aging on the architecture of the ileocecal junction in rats
Maria Cícera de Brito, Renato Paulo Chopard, Diego Pulzatto Cury, Ii Sei Watanabe, Cristina Eusébio Mendes, Patricia Castelucci
Maria Cícera de Brito, Diego Pulzatto Cury, Department of Surgery, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo 05508-900, Brazil
Renato Paulo Chopard, Diego Pulzatto Cury, Ii Sei Watanabe, Cristina Eusébio Mendes, Patricia Castelucci, Department of Anatomy/Biomedical Science Institute, University of São Paulo, São Paulo 05508-900, Brazil
Author contributions: de Brito MC performed all of the experiments and analyzed the results for this work; Chopard RP planned experiments; Cury DP and Watanabe IS helped and analyzed the transmission and scan electron microscopy studies; Mendes CE helped edit the manuscript and figures; Castelucci P planned the immunohistochemistry study, wrote and edit the manuscript.
Institutional review board statement: This study approved in the meeting of day 2/19/2014 and agree with Ethical principles in animal research adopted by ethic committee in the use of animals of the school of veterinary medicine and animal science of University of São Paulo.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article were reported.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Patricia Castelucci, PhD, Associate Professor, Department of Anatomy/Biomedical Science Institute, University of São Paulo, R. Dr. Lineu Prestes 2415, São Paulo 05508-900, Brazil. pcastel@usp.br
Telephone: +55-11-30918463 Fax: +55-11-30917366
Received: January 3, 2016
Peer-review started: January 4, 2016
First decision: February 26, 2016
Revised: March 15, 2016
Accepted: April 5, 2016
Article in press: April 6, 2016
Published online: August 6, 2016
Processing time: 211 Days and 7.1 Hours
Abstract

AIM: To evaluate the structural organization of the elastic and collagen fibers in the region of the ileocecal transition in 30 young and old male Wistar rats.

METHODS: Histology, immunohistochemistry (IHC), transmission electron microscopy and scanning electron microscopy were employed in this study. The results demonstrated that there was a demarcation of the ileocecal region between the ileum and the cecum in both groups.

RESULTS: The connective tissue fibers had different distribution patterns in the two groups. IHC revealed the presence of nitric oxide synthase, enteric neurons and smooth muscle fibers in the ileocecal junctions (ICJs) of both groups. Compared to the young group, the elderly group exhibited an increase in collagen type I fibers, a decrease in collagen type III fibers, a decreased linear density of oxytalan elastic fibers, and a greater linear density of elaunin and mature elastic fibers.

CONCLUSION: The results revealed changes in the patterns of distribution of collagen and elastic fibers that may lead to a possible decrease in ICJ functionality.

Keywords: Ileocecal junction; Elastic fibers; Collagen fibers; Aging; Rats

Core tip: The ileocolonic sphincter controls the forward and backward flow by integrating its motility with that of the distal ileum and proximal the ileocolonic sphincter controls the forward and backward flow by integrating its motility with that of the distal ileum and proxima. The ileocecal junction (ICJ) includes the muscle bundles in the terminal ileum, the intrinsic nerve plexus. The ICJ includes the muscle bundles in the terminal ileum, the intrinsic nerve plexus. Given the importance of knowing how the ICJ changes with age, the objective of this study was to characterize the morphological changes in the ICJ in rats aged 21 d and 2 years, using optical microscopy and electronic scanning and transmission methodologies. Additionally, the neurochemical characterization of the inhibitory neurons of the myenteric plexus, which are immunoreactive to the enzyme nitric oxide synthase, and the staining of the neuronal population were employed to identify immunoreactivity to HuC/D.