Prolonged contraction-relaxation cycle of fast-twitch  muscles in parvalbumin knockout mice

Schwaller, B.; Dick, J.; Dhoot, G.; Carroll, S.; Vrbova, G.; Nicotera, P.; Pette, D.; Wyss, A.; Bluethmann, H.; Hunziker, W.; Celio, M. R.

doi:10.1152/ajpcell.1999.276.2.c395

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Journal article

Prolonged contraction-relaxation cycle of fast-twitch muscles in parvalbumin knockout mice

Schwaller, B. Institute of Histology and General Embryology and “Program in Neuroscience,” University of Fribourg, CH-1705 Fribourg, Switzerland;
Dick, J. Department of Anatomy, University College, London WC1E 6BT;
Dhoot, G. Royal Veterinary College, London NW1 0TU, United Kingdom;
Carroll, S. Institute of Toxicology, Faculty of Biology, University of Constance, D-78457 Constance, Germany; and
Vrbova, G. Department of Anatomy, University College, London WC1E 6BT;
Nicotera, P. Institute of Toxicology, Faculty of Biology, University of Constance, D-78457 Constance, Germany; and
Pette, D. Institute of Toxicology, Faculty of Biology, University of Constance, D-78457 Constance, Germany; and
Wyss, A. Roche Vitamins Division, Hoffmann-LaRoche, 4070 Basel, Switzerland
Bluethmann, H. Roche Vitamins Division, Hoffmann-LaRoche, 4070 Basel, Switzerland
Hunziker, W. Roche Vitamins Division, Hoffmann-LaRoche, 4070 Basel, Switzerland
Celio, M. R. Institute of Histology and General Embryology and “Program in Neuroscience,” University of Fribourg, CH-1705 Fribourg, Switzerland;

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American Journal of Physiology-Cell Physiology. - American Physiological Society. - 1999, vol. 276, no. 2, p. C395-C403

English The calcium-binding protein parvalbumin (PV) occurs at high concentrations in fast-contracting vertebrate muscle fibers. Its putative role in facilitating the rapid relaxation of mammalian fast-twitch muscle fibers by acting as a temporary buffer for Ca2+ is still controversial. We generated knockout mice for PV (PV −/−) and compared the Ca2+ transients and the dynamics of contraction of their muscles with those from heterozygous (PV +/−) and wild-type (WT) mice. In the muscles of PV-deficient mice, the decay of intracellular Ca2+ concentration ([Ca2+]i) after 20-ms stimulation was slower compared with WT mice and led to a prolongation of the time required to attain peak twitch tension and to an extension of the half-relaxation time. The integral [Ca2+]iin muscle fibers of PV −/− mice was higher and consequently the force generated during a single twitch was ∼40% greater than in PV +/− and WT animals. Acceleration of the contraction-relaxation cycle of fast-twitch muscle fibers by PV may confer an advantage in the performance of rapid, phasic movements.

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