caa a22 4500 469030402 CHVBK 20180323132742.0 cr unu---uuuuu 170328e19920701xx s 000 0 eng 10.1007/BF01089105 doi (NATIONALLICENCE)springer-10.1007/BF01089105 Quantitative determination of calcium-activated myosin adenosine triphosphatase activity in rat skeletal muscle fibres [Elektronische Daten] [Cesar Blanco, Gary Sieck] Summary: A quantitative histochemical technique was developed for determining the kinetics of the calcium-activated myosin ATPase (Ca2+-myosin ATPase) reaction in rat skeletal muscle fibres. Using this technique, the maximum velocity (Vmax) and the apparent Michaelis-Menten rate constant for ATP (Kapp) of the Ca2+-myosin ATPase reaction were measured in type-identified fibres of the rat medial gastrocnemius (MG) muscle. The Vmax and the Kapp of the Ca2+-myosin ATPase reaction were lowest in type I fibres and highest (i.e., approx. two times greater) in type IIb fibres. The Kapp in type IIa fibres was similar to that in type I. However, the Vmax was 1.5 times greater in type IIa fibres, compared to type I fibres. Evidence is presented to suggest that the type IIb fibre population in the MG does not represent a single myosin isozyme. In addition, the broad range of Vmax and Kapp values indicates that there is marked heterogeneity in the myosin heavy chain and myosin light chain composition of myosin isozymes among individual fibres. Chapman & Hall, 1992 Blanco Cesar Departments of Anesthesiology and Physiology and Biophysics, Mayo Clinic and Mayo Foundation, 55905, Rochester, MN, USA aut Sieck Gary Departments of Anesthesiology and Physiology and Biophysics, Mayo Clinic and Mayo Foundation, 55905, Rochester, MN, USA aut The Histochemical Journal Kluwer Academic Publishers 24/7(1992-07-01), 431-444 0018-2214 24:7<431 1992 24 10735 https://doi.org/10.1007/BF01089105 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01089105 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Blanco Cesar Departments of Anesthesiology and Physiology and Biophysics, Mayo Clinic and Mayo Foundation, 55905, Rochester, MN, USA aut NATIONALLICENCE 700 1- Sieck Gary Departments of Anesthesiology and Physiology and Biophysics, Mayo Clinic and Mayo Foundation, 55905, Rochester, MN, USA aut NATIONALLICENCE 773 0- The Histochemical Journal Kluwer Academic Publishers 24/7(1992-07-01), 431-444 0018-2214 24:7<431 1992 24 10735 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer