No Difference in Myosin Kinetics and Spatial Distribution of the Lever Arm in the Left and Right Ventricles of Human Hearts.

Autor:	Duggal D; Department of Cell Biology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, TX, United States., Requena S; Department of Cell Biology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, TX, United States., Nagwekar J; Department of Cell Biology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, TX, United States., Raut S; Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX, United States., Rich R; Department of Mathematics and Physics, Texas Wesleyan University, Fort Worth, TX, United States., Das H; Center for Neuroscience Discovery, Institute for Healthy Aging, University of North Texas, Health Science Center, Fort Worth, TX, United States., Patel V; Department of Cell Biology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, TX, United States.; Center of Emphasis in Diabetes and Metabolism, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, TX, United States., Gryczynski I; Department of Cell Biology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, TX, United States., Fudala R; Department of Cell Biology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, TX, United States., Gryczynski Z; Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX, United States., Blair C; Department of Physiology, University of Kentucky, Lexington, KY, United States., Campbell KS; Department of Physiology, University of Kentucky, Lexington, KY, United States., Borejdo J; Department of Cell Biology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, TX, United States.
Jazyk:	angličtina
Zdroj:	Frontiers in physiology [Front Physiol] 2017 Oct 13; Vol. 8, pp. 732. Date of Electronic Publication: 2017 Oct 13 (Print Publication: 2017).
DOI:	10.3389/fphys.2017.00732
Abstrakt:	The systemic circulation offers larger resistance to the blood flow than the pulmonary system. Consequently, the left ventricle (LV) must pump blood with more force than the right ventricle (RV). The question arises whether the stronger pumping action of the LV is due to a more efficient action of left ventricular myosin, or whether it is due to the morphological differences between ventricles. Such a question cannot be answered by studying the entire ventricles or myocytes because any observed differences would be wiped out by averaging the information obtained from trillions of myosin molecules present in a ventricle or myocyte. We therefore searched for the differences between single myosin molecules of the LV and RV of failing hearts In-situ . We show that the parameters that define the mechanical characteristics of working myosin (kinetic rates and the distribution of spatial orientation of myosin lever arm) were the same in both ventricles. These results suggest that there is no difference in the way myosin interacts with thin filaments in myocytes of failing hearts, and suggests that the difference in pumping efficiencies are caused by interactions between muscle proteins other than myosin or that they are purely morphological.
Databáze:	MEDLINE
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