Interfilament Spacing is Preserved During Sarcomere Length Isometric Contractions in Rat Cardiac Trabeculae.
From: Center for Cardiovascular Research, Department of Physiology and Biophysics, University of Illinois College of Medicine, Chicago, Illinois 60612-7342, USA.
Biophysical journal
- Publish Date: May 2007
- ISSN: 0006-3495
- Volume: 92
- Issue: 9
- Pages: L73-5
- Medium: Print
- Language: English
- Citation (JAMA): Farman Gerrie P, Allen Edward J, Gore David, et al. Interfilament Spacing is Preserved During Sarcomere Length Isometric Contractions in Rat Cardiac Trabeculae.. Biophys. J. May 2007;92:L73-5
Abstract
It is generally assumed that the myofilament lattice in intact (i.e., nonskinned) striated muscle obeys constant volume. However, whether such is the case during the myocardial contraction is unknown. Accordingly, we measured interfilament spacing by x-ray diffraction in ultra-thin isolated rat right ventricular trabeculae during a short 10 ms shuttered exposure either just before electrical stimulation (diastole), or at the peak of the contraction (systole); sarcomere length (SL) was held constant throughout the contraction using an iterative feedback control system. SL was thus varied in a series of SL-clamped contractions; the relationship between SL and interfilament spacing was not different between diastole and systole within 1%; this was true also over a wide range of inotropic states induced by varied [Ca(2+)](o). We conclude that the cardiac myofilament lattice maintains constant volume, and thus constant interfilament spacing, during contraction.
Mesh Headings (Keywords): Animals, Cells, Cultured, Isometric Contraction, Male, Myocardial Contraction, Myocytes, Cardiac, Rats, Sarcomeres
Check for Full Text / PubMed Unique Identifier (PMID): 17293398
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.