caa a22 4500 475745124 CHVBK 20180406123511.0 cr unu---uuuuu 170329e20000501xx s 000 0 eng 10.1023/A:1005679215704 doi (NATIONALLICENCE)springer-10.1023/A:1005679215704 Length-dependent effects of osmotic compression on skinned rabbit psoas muscle fibers [Elektronische Daten] [Yi-Peng Wang, Franklin Fuchs] The goal of this study was to characterize the interrelationship between sarcomere length and interfilament spacing in the control of Ca2+ sensitivity in skinned rabbit psoas muscle fibers. Measurements were made at sarcomere lengths 2.0, 2.7 and 3.4 μm. At 2.7 μm the fiber width was reduced by 17% relative to that at 2.0 μm and the pCa50 for force development was increased by ∼0.3 pCa units. In the presence of 5% Dextran T-500 the fiber width at sarcomere length 2.0 μm was also decreased by 17% and the Ca2+ sensitivity was increased to the same value as at 2.7 μm. In contrast, at sarcomere length 2.7 μm the addition of as much as 10% Dextran T-500 had no effect on Ca2+ sensitivity. At sarcomere length 3.4 μm there was an additional 7% compression and the Ca2+ sensitivity was increased slightly (∼0.1 pCa units) relative to that at 2.7 μm. However at 3.4 μm the addition of 5% Dextran T-500 caused the Ca2+ sensitivity to decrease to the level seen at 2.0 μm. Given that the skinning process causes a swelling of the filament lattice it is evident that the relationship between sarcomere length and Ca2+ sensitivity observed in skinned fibers may not always be applicable to intact fibers. These data are consistent with measurements of Ca2+ in intact fibers which indicate that there might be a decline in Ca2+ sensitivity at long sarcomere lengths. Kluwer Academic Publishers, 2000 Wang Yi-Peng Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, 15261, Pittsburgh, PA, USA aut Fuchs Franklin Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, 15261, Pittsburgh, PA, USA aut Journal of Muscle Research & Cell Motility Kluwer Academic Publishers 21/4(2000-05-01), 313-319 0142-4319 21:4<313 2000 21 10974 https://doi.org/10.1023/A:1005679215704 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1005679215704 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wang Yi-Peng Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, 15261, Pittsburgh, PA, USA aut NATIONALLICENCE 700 1- Fuchs Franklin Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, 15261, Pittsburgh, PA, USA aut NATIONALLICENCE 773 0- Journal of Muscle Research & Cell Motility Kluwer Academic Publishers 21/4(2000-05-01), 313-319 0142-4319 21:4<313 2000 21 10974 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer