Effect of vanadate on Ca++-activation in skeletal muscle
Son'kin, B.I.; Bukatina, A.E.
Biofizika 28(5): 886-888
1983
ISSN/ISBN: 0006-3029 PMID: 6556917 Document Number: 218202
Vanadate (0.1 mM) reduces tension of glycerinated rabbit psoas muscle fibers, shifts tension--pCa curve to lower pCa, increases the rate constant of delayed tension development and changes dependence of this rate constant on the level of Ca2+-activation. Vanadate influence stops the increase of the rate constant with the rise of Ca++-activated tension. Since actin-myosin-ADP complex is dissociated by vanadate, the muscle performance at low activation levels is supposed to be conditioned largely by the cross-bridges interacting with actin of the actin blocks switched on by myosin-ADP. Kinetics of such cross-bridges differs from that of the cross bridges interacting with actin activated by Ca++ binding to troponin C.