[Kinetic characteristics of cross bridges in the heart muscles by a temperature jump method].
Experiments were performed on rat skinned trabecular muscles dissected from the right ventricles. They were activated (pCa = 5.9) at 10 C, 2.3 nm sarcomere length. The temperature jump induced the biexponential tension rise. The rate constant of the fast tension rise (k1) was 3-4.5 ms and that of the slow tension rise (k2) was about 15 ms. These values were slower (3 times) comparing with those of a single skeletal fibre. The discrepancy can be explained by different kinetic properties of heart and skeletal myosin or presents a well developed connection tissue (series elastic element) in the heart muscle.
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D000818:Animals; D006321:Heart / Q000502:physiology*; D007700:Kinetics; D009210:Myofibrils / Q000502:physiology; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D013696:Temperature
Izuchenie kineticheskikh karakteristik poperechnykh mostikov v serdechnoĭ myshtse metodom skachka temperatury.