This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Schwertz, D. W. Articles by Ross, J. D. Search for Related Content PubMed PubMed Citation Articles by Schwertz, D. W. Articles by Ross, J. D. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB CALCIUM COMPOUNDS CALCIUM, ELEMENTAL Social Bookmarking                   What's this?

Sex Differences in the Response of Rat Heart Ventricle to Calcium

Medical Surgical Nursing, Schwertz{at}uic.edu

Jenny M. Beck, BS

College of Nursing at the University of Illinois at Chicago

Jill M. Kowalski, BS, MS

College of Nursing at the University of Illinois at Chicago

James D. Ross, BA

College of Medicine at the University of Illinois at Chicago

Calcium (Ca ²⁺ ) is a key mediator of myocardial function. Calcium regulates contraction, and disruption of myocellular Ca ²⁺ handling plays a role in cardiac pathologies such as arrhythmias and heart failure. This investigation examines sex differences in sensitivity of the contractile proteins to Ca ²⁺ and myofibrillar Ca ²⁺ delivery in the ventricular myocardium. Sensitivity of contractile proteins to Ca ²⁺ was measured in weight-matched male and female Sprague-Dawley rats using the skinned ventricular papillary muscle fiber and Ca ²⁺ -stimulated Mg ²⁺ -dependent adenosine triphosphatase (ATPase) activity methodologies. Calcium delivery was examined by measuring the contractile response to a range of extracellular Ca ²⁺ concentrations in isolated ventricular myocytes, papillary muscle, and the isolated perfused whole heart. Findings from studies in the whole heart suggest that at a fixed preload, the male left ventricle generates more pressure than a female ventricle over a range of extracellular Ca ²⁺ concentrations. In contrast, results from myocyte and papillary muscle studies suggest that females require less extracellular Ca ²⁺ to elicit a similar contractile response. Results obtained from the 2 methods used to determine sex differences in Ca ²⁺ sensitivity were equivocal. Further studies are required to elucidate sex differences in myocardial Ca ²⁺ handling and the reasons for disparate results in different heart muscle preparations. The results of these studies will lead to the design of sex-optimized therapeutic interventions for cardiac disease.

Key Words: sex difference • heart • myocyte • papillary • calcium • calcium sensitivity • force • contraction • skinned fibers • myofibrillar ATPase • rat

Biological Research For Nursing, Vol. 5, No. 4, 286-298 (2004)
DOI: 10.1177/1099800403262615


CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				N. Yaras, E. Tuncay, N. Purali, B. Sahinoglu, G. Vassort, and B. Turan Sex-related effects on diabetes-induced alterations in calcium release in the rat heart Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3584 - H3592. [Abstract] [Full Text] [PDF]