Stretching of rabbit psoas muscle fibers increases the rate of ATP splitting, suggesting an increased interaction cycle between actin and myosin molecules.
Animal data on rabbit skeletal muscle leave open translation to human cardiac sarcomeres; extends basic actin-myosin interaction models but requires validation.
The effect of sarcomere length and stretching on the tension and the rate of ATP splitting was studied using small fiber bundles from glycerinated rabbit psoas muscle. The rate of ATP slitting was determined by measuring ADP production, while the tension development in response to a contracting solution (at pCa 5.3) was recorded in the same preparation. The isometric tension developed by the preparation decreased when the sarcomere length was increased. The decrease of tension development was accompanied by a decrease in the rate of ATP splitting. If a preparation exerting steady isometric tension was stretched by 5--10% at a velocity of 0.1 mm/s, the rate of ATP splitting was increased after stretching, while the steady isometric tension attained after stretching was also higher than the initial value. The extent of the excess ATP splitting caused by stretching decreased with increasing sarcomere length. These results suggest that the rate of the interaction cycle between actin and myosin molecules may increase as a result of stretching.
No takes yet. Share an insight, caveat, or question.
Tanaka et al. (1979) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: