@article {Coirault1055, author = {C Coirault and P Attal and FX Blanc and D Chemla and Y Lecarpentier}, title = {Cross-bridge kinetics in fatigued mouse diaphragm}, volume = {13}, number = {5}, pages = {1055--1061}, year = {1999}, doi = {10.1034/j.1399-3003.1999.13e20.x}, publisher = {European Respiratory Society}, abstract = {The aim of this study was to determine cross-bridge number and kinetics in the diaphragm during fatigue and early recovery. Experiments were conducted in isolated mouse diaphragm (n=10). The force of a single cross-bridge (pi), the number of cross-bridges (m x 10(9) x mm2), the time cycle (tc) and the rate constants for cross-bridge attachment (f1) and detachment (g2) were calculated from the equations of A.F. Huxley. Following the fatigue protocol, peak isometric tension (Po) and maximum unloaded shortening velocity fell by 40+/-1\% and 17+/-2\%, respectively. In fatigued diaphragm, m fell by approximately 40\% and returned to baseline after 10 min. When compared to baseline, g2 fell in fatigued diaphragm and remained significantly lower during the 15-min recovery period. In contrast, fatigue did not significantly modify pi, f1, or tc. There was a strong linear relationship between Po and m (p\<0.001, r=0.988). No relationship was observed between tc and g2. These results indicate that changes in tension during fatigue and recovery run parallel to changes in the number of active cross-bridges, with no change in the force generated per cross-bridge. It is conceivable that fatigue durably impairs adenosine diphosphate release from the actomyosin complex without modifying the total duration of the cross-bridge cycle.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/13/5/1055}, eprint = {https://erj.ersjournals.com/content/13/5/1055.full.pdf}, journal = {European Respiratory Journal} }