Detail Sex Differences in the Response of Rat Heart Ventricle to Calcium Bibliografi Author: Schwertz, Dorie W. ; Ross, James D. (Co-Author); Beck, Jenny M. (Co-Author); Jill M. Kowalski B. S. (Co-Author) Topik: sex difference; papillary; calcium sensitivity; contraction; myofibrillar ATPase; rat; skinned fibers; force; calcium; myocyte; heart Bahasa: (EN )     Penerbit: SAGE Publications     Tempat Terbit: London    Tahun Terbit: 2004     Jenis: Article - untuk jurnal ilmiah Fulltext: 286BRN54.pdf (154.0KB; 1 download) Abstract Calcium (Ca2+) is a key mediator of myocardial function. Calcium regulates contraction, and disruption of myocellular Ca2+ 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 Ca2+ and myofibrillar Ca2+ delivery in the ventricular myocardium. Sensitivity of contractile proteins to Ca2+ was measured in weight-matched male and female Sprague-Dawley rats using the skinned ventricular papillary muscle fiber and Ca2+- stimulated Mg2+-dependent adenosine triphosphatase (ATPase) activity methodologies. Calcium delivery was examined by measuring the contractile response to a range of extracellular Ca2+ 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 Ca2+ concentrations. In contrast, results from myocyte and papillary muscle studies suggest that females require less extracellular Ca2+ to elicit a similar contractile response. Results obtained from the 2 methods used to determine sex differences in Ca2+ sensitivity were equivocal. Further studies are required to elucidate sex differences in myocardial Ca2+ 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. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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