- 作者: Kadon K. Hintz Loren E. Wold Peter B. Colligan Glenda I. Scott Kap J. Lee james R. Sowers Jun Ren
- 作者服務機構: Department of Pharmacology, Physiology and Therapeutics, Center for Biomedical Research, University of North Dakota School of Medicine, Grand Forks, N. Dak., Depatrment of Medicine, State University of New York Downstate Medical Center and Brooklyn VA, Brooklyn, N.Y., USA
- 中文摘要: --
- 英文摘要: We studied the effect of ovariectomy (OVX) on cardiaccontraction in myocytes maintained under a'diabetes-simulated high-glucose' environment. Female rats wereovariectomized or sham operated (SHAM) and kept for 6weeks. Isolated myocytes were maintained in a diabetes-simulated high [glucose] medium (HG;25.5 mM) for 24 hbefore mechanical properties were measured. Contrac-tile indices analyzed included peak shortening (PS), timeto PS (TPS), time to 90% relengthening (TR ), maximalvelocity of shortening and relengthening ( dL/dt), intra-cellular Ca fura-2 fluorescence intensity and decay rate( ). Nitric oxide synthase (NOS) activity was also evalu-ated. OVX myocytes displayed a longer TR , slower dL/dt, lower fluorescence intensity and higher (slowerdecay rate ) when compared to SHAM myocytes. In theSHAM group, HG exerted diabetes-like contractile dys-functions, including depressed PS, prolonged TR , re-duced fluorescence intensity, higher and enhancedNOS activity when compared to myocytes maintained inlow [glucose] medium (5.5mM). Interestingly, the HG-induced mechanical alterations were significantly exag-gerated (TPS, TR and ) , reversed (PS and NOS) or lost( dL/dt and fluorescence intensity) in the OVX group.These data suggest that ovarian hormones play a role inthe regulation of cardiac contractile function, and mayhave potentially protective effects against diabetes-asso-ciated cardiac dysfunction.
- 中文關鍵字: --
- 英文關鍵字: Ovariectomy. Diabetes. Cardiac. Contraction