Summary
The effects of amrinone were studied on single skinned fibres isolated from rat hindlimb muscles. In each fibre a force-velocity relation was determined during maximal calcium activation (pCa=4.45) in control conditions and in the presence of amrinone. The MgATP concentration was 3.93 mm, close to the physiological value. After the experiment the fibre was classified as fast or slow on the basis of its reactivity with anti-myosin monoclonal antibodies. In fast fibres amrinone (3 mm) potentiated isometric tension (P 0) by 13.8±2.9% (n=13), reduced maximum shortening velocity (V max ) by 32.6±3.2% and the curvature of the force-velocity relation (a/P 0) was increased by 98.9±46.0%. All these effects were less pronounced in slow fibres, where V max was reduced only by 11.4±3.6 (n=16). The effects of amrinone (0.3–6 mm) on the ATPase activity of myofibrils and myosin prepared from fast (tibialis anterior) and slow (soleus) rat skeletal muscles were studied. Amrinone was found to depress Ca−Mg dependent ATPase activity of myofibrillar preparations of the tibialis anterior (up to 16.6±2%) and, to a lesser extent, of the soleus (up to 7.2±1.2%). On the contrary, Ca-stimulated myosin ATPase activity was significantly increased by amrinone in myosin preparations from the tibialis anterior. Experiments were carried out to test whether amrinone (3 mm) might affect the sensitivity of the contractile system to MgATP concentration ([MgATP]). The results obtained showed that (1) the [MgATP] value at which isometric tension reached its maximum was shifted by amrinone from 0.1 mm to 0.3 mm, (2) the slope of the negative relation between [MgATP] and a/P 0 was made more steep by amrinone, and (3) the Km of the hyperbolic relation between [MgATP] and V max was increased from 0.39 to 1.71 mm by amrinone, thus indicating a reduced affinity of myosin for MgATP. These results are in accordance with the hypothesis that amrinone exerts a direct effect on the contractile mechanism.
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References
ALOUSI, A. A., FARAH, A. E., LESHER, G. Y. & OPALKAJr., C. J. (1979) Cardiotonic activity of amrinone-WIN 40680 [5-amino-3,4-bipiridine-6(iH)-one]. Circ. Res. 45, 666–77.
ARIANO, M. A., ARMSTRONG, R. B. & EDGERTON, V. R. (1973) Hindlimb muscle fibre population of five mammals. J. Histochem. Cytochem. 21, 51–5.
AARANY, M. (1967) ATPase activity of myosin correlated with speed of muscle shortening. J. Gen. Physiol. 50, 197–216.
BOTTINELLI, R., CAPPELLI, V., MORNER, J. & REGGIANI, C. (1989) Amrinone decreases maximum velocity of shortening and myofibrillar ATPase activity in fast mammalian skeletal muscle. Proceedings of the International Union of Physiological Sciences XVII P2445 p. 192.
AOTTINELLI, R., SCHIAFFINO, S. & REGGIANI, C. (1991) Force-velocity relations and myosin heavy chain isoform composition of skinned fibres from rat skeletal muscle. J. Physiol. (Lond.) 437, 655–72.
ARENNER, B. (1986) The crossbridge cycle in muscle. Mechanical, biochemical and structural studies on single skinned rabbit psoas fibers to characterize crossbridge kinetics in muscle for correlation with actomyosin ATPase in solution. Basic Res. Cardiol. 81 (Suppl. 1), 1–15.
ARENNER, B. (1990) Muscle mechanics and biochemical kinetics. In Molecular Mechanism in Muscular Contraction (edited by SQUIRE, J. M.) London: Macmillan Press.
ARENNER, B. & EISENBERG, E. (1987) The mechanism of muscle contraction. Biochemical, mechanical and structural approaches to elucidate crossbridge action in muscle. Basic Res. Cardiol. 82 (Suppl 1), 3–16.
CAPPELLI, C., MOGGIO, R., POLLA, B., AOTTINELLI, R., POGGESI, C. & REGGIANI, C. (1988) The dual effect of thyroid hormones on contractile properties of rat myocardium. Pflügers Arch. 411, 620–7.
CECCHI, G., LOMBARDI, V. & MENCHETTI, G. (1984) Development of force-velocity relation and rise of isometric tetanic tension measure the time course of different processes. Pflügers Arch. 401, 396–401.
COOKE, R. & AIALEK, W. (1979) Contraction of glycerinated muscle fibres as a function of the ATP concentration. Biophys. J. 28, 241–68.
EDMAN, K. A. P. (1979) The velocity of unloaded shortening and its relation to sarcomere length and isometric force in vertebrate muscle fibres. J. Physiol. (Lond.) 291, 143–59.
EDMAN, K. A. P. & FLITNEY, F. W. (1982) Laser diffraction studies of sarcomere dynamics during isometric relaxation in isolated muscle fibres of the frog. J. Physiol. (Lond.) 329, 1–20.
EDMAN, K. A. P. & REGGIANI, C. (1984) Redistribution of sarcomere length during isometric contraction of frog muscle fibres and its relation to tension creep. J. Physiol. (Lond.) 351, 169–98.
EDMAN, K. A. P., MULIERI, L. A. & SCUBON-MULIERI, B. (1976) Non-hyperbolic force-velocity relationship in single muscle fibres. Acta Physiol. Scand. 98, 143–56.
EISENBERG, E. & MOOS, C. (1968) The ATPase activity of acto-heavy meromyosin. A kinetic analysis of actin activation. Biochemistry 7, 1486–9.
EISENBERG, E., HILL, T. L. & CHEN, Y. (1980) Crossbridge model of muscle contraction. Quantitative analysis. Biophys. J. 29, 195–227.
ENDOH, M., YAMASHITA, S. & TAIRA, N. (1982) Positive inotropic effect of amrinone in relation to cyclic nucleotide metabolism in the canine ventricular muscle. J. Pharmacol. Exp. Ther. 221, 775–83.
FABIATO, A. (1988) Computer programs for calculating total from specific free or free from specified total ionic concentrations in aqueous solutions containing multiple metals and ligands. Methods Enzymol. Biomemb. 157, 378–417.
FERENCZI, M. A., GOLDMAN, Y. E. & SIMMONS, R. M. (1984) The dependence of force and shortening velocity on substrate concentration in skinned muscle fibres from Rana temporaria. J. Physiol. (Lond.) 350, 519–43.
FISKE, C. H. & SUBBAROW, Y. (1925) The colorimetric determination of phosphorus. J. Biol. Chem. 66, 375–400.
FRYER, M. W., NEERING, I. R. & STEPHENSON, D. G. (1988) Effects of 2,3 butanedione monoxime on the contractile activation properties of fast and slow twitch rat muscle fibres. J. Physiol. (Lond.) 407, 53–75.
GONZALES SERRATOS, H., HILL, L. & VALLE-AGUILERA, R. (1981) Effects of catecholamines and cyclic AMP on excitation-contraction coupling in isolated skeletal muscle fibres of the frog. J. Physiol. (Lond.) 315, 267–82.
HONERJAGER, P., SHAFER-KORTING, M. & REITER, M. (1981) Involvement of cyclic AMP in the direct inotropic action of amrinone. Biochemical and functional evidence. Naunyn-Schmiedeberg's Arch. Pharmacol. 318, 112–20.
HORIUTI, K., HIGUCHI, H., UMAZUME, Y., KONISHI, M., OKOZAKI, O. & KURIHARA, S. (1988) Mechanism of action of 2,3 butanedione 2 monoxime on contraction of frog skeletal muscle fibres. J. Muscle Res. Cell Motil. 9, 156–64.
HUXLEY, A. F. (1957) Muscle structure and theories of contraction. Prog. Biophys. Biophys. Chem. 7, 255–318.
LOWRY, O. H., ROSEBROUGH, N. J., FARR, A. L. & RANDALL, R. J. (1951) Protein measurement with the folin fenol reagent. J. Biol. Chem. 193, 265–75.
MÅNSSON, A. & EDMAN, K. A. P. (1984) Effects of amrinone on twitch, tetanus and force-velocity relationship in frog skeletal muscle. Acta Physiol. Scand. 120, 473–5.
MÅNSSON, A. & EDMAN, K. A. P. (1985) Effects of amrinone on the contractile behaviour of frog striated muscle fibres. Acta Physiol. Scand. 125, 481–93.
MÅNSSON, A., MÖRNER, J. & EDMAN, K. A. P. (1989) Effects of amrinone on twitch, tetanus and shortening kinetics in mammalian skeletal muscle. Acta Physiol. Scand. 136, 37–45.
MEISHERI, K. D., PALMER, R. F. & VanAREEMEN, C. (1980) The effects of amrinone on contractility, Ca uptake and cAMP in smooth muscle. Eur. J. Pharmacol. 61, 159–65.
PATE, E. & COOKE, R. (1989) A model of crossbridge action: the effects of ATP, ADP and Pi. J. Muscle Res. Cell Motil. 10, 181–96.
SIEGL, P. K. S., MORGAN, G. & SEETS, C. S. (1984) Responses to amrinone in isolated cardiac muscles from cat, rabbit and guinea pig. J. Cardiovasc. Pharmacol. 6, 281–7.
STEPHENSON, D. G. & WILLIAMS, D. A. (1982) Effects of sarcomere length on the force-pCa relation in fast- and slow twitch skinned muscle fibres from the rat. J. Physiol. (Lond.) 333, 637–53.
STEIN, R. B., GORDON, T. & SHRIVER, J. (1982) Temperature dependence of mammalian muscle contractions and ATPase activities. Biophys. J. 40, 97–107.
STIENEN, G. J. M. & ROOSEMALEN, M. C. M. (1988) Different crossbridge dissociation rates in skinned muscle fibres of rabbit soleus and psoas muscle. Biophys. J. 53, 193a.
STIENEN, G. J. M., Van DerLAARSE, W. J. & ELZINGA, G. (1988) Dependency of the force-velocity relationships on Mg ATP in different types of muscle fibres from Xenopus laevis. Biophys. J. 53, 849–55.
TAYLOR, E. W. (1972) Chemistry of muscle contraction. Ann. Rev. Biochem. 41, 577–616.
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Aottinelli, R., Cappelli, V., Morner, S.E.J.N. et al. Effects of amrinone on shortening velocity and force development in skinned skeletal muscle fibres. J Muscle Res Cell Motil 14, 110–120 (1993). https://doi.org/10.1007/BF00132185
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DOI: https://doi.org/10.1007/BF00132185