Contractile Properties and Myosin Heavy Chain Composition of Rat Tongue Retrusor Musculature Show Changes in Early Adulthood After 19 Days of Artificial Rearing.
From: Department of Anatomy and Neurobiology, Virginia Commonwealth University, P.O. Box 980709, Richmond, 23298-0709, USA. jcsmith@vcu.edu
Journal of applied physiology (Bethesda, Md. : 1985)
- Publish Date: Oct 2006
- ISSN: 8750-7587
- Volume: 101
- Issue: 4
- Pages: 1053-9
- Medium: Print
- Language: English
- Citation (JAMA): Smith J Chadwick, Moore W Allen, Goldberg Stephen J, et al. Contractile Properties and Myosin Heavy Chain Composition of Rat Tongue Retrusor Musculature Show Changes in Early Adulthood After 19 Days of Artificial Rearing.. J. Appl. Physiol. Oct 2006;101:1053-9
Abstract
Previously, we showed that artificial rearing using the “pup in a cup” model results in decreased tongue activity and caused some minor alterations in the tongue retrusor musculature. However, the artificial rearing time frame previously chosen was brief (11 days). The purpose of the present investigation was to extend the artificial rearing period from postnatal days 3 to 21 (P21) to determine whether significant alterations occur as a result of this reduced tongue use. Several changes in contractile properties due to the artificial rearing process were observed, which fully recovered by postnatal days 41 to 42 (P41-2). These changes included a shorter twitch contraction time, shorter twitch half-relaxation time, and decreased fatigue resistance. Styloglossus muscle exhibited more neonatal myosin heavy chain (MHC) isoform at P21 for the artificially reared (AR) group. Changes that were persistent at P41-2 were also observed. Maximum tetanic tension was lower for the AR group at P21 and P41-2 compared with their dam-reared counterparts. Twitch tension was also lower by P41-2 in the AR group. At P41-2, the AR group exhibited an increase in MHC IIa and a decrease in MHC IIb for the styloglossus muscle. In addition, the AR group exhibited a decreased MHC IIb for the long head of the biceps brachii at P41-2. Our results are similar to other models of hindlimb immobilization and suspension. By extending our artificial rearing period, this reduced tongue activity induced acute changes and alterations in the tongue retrusor musculature that persisted into early adulthood.
Mesh Headings (Keywords): Animal Husbandry, Animals, Animals, Newborn, Animals, Suckling, Electromyography, Enteral Nutrition, Muscle Contraction, Muscle, Skeletal, Myosin Heavy Chains, Protein Isoforms, Rats, Rats, Sprague-Dawley, Sucking Behavior, Tongue
Check for Full Text / PubMed Unique Identifier (PMID): 16809631
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.