Abstract
We studied the mechanisms of action of a negative inotropic compound, 2,3-butanedione-monoxime (BDM), which has been suggested to be a cardioprotective agent.
In guinea-pig papillary muscles the negative inotropic effect of BDM started at 100 μmol/l amounting to 18.32±2.09% of predrug value at 10 mmol/l without any effects on time parameters (n = 12, each). 30 mmol/l BDM totally abolished force of contraction; this effect was reversible after washout. In the presence of the phosphatase-inhibitor cantharidin (30 μmol/l) the concentration response curve on force of contraction was shifted to higher concentrations of BDM.
100 mmol/l BDM decreased the phosphorylation state of the inhibitory subunit of troponin (TnI) and phospholamban (PLB) in [32P]-labeled guinea-pig ventricular myocytes to 76.5±4.7% and 49.7±4.2%, respectively (n = 7). Furthermore, BDM enhanced the activity of phosphorylase phosphatases in guinea-pig ventricular homogenates amounting to a stimulation to 203.5±10.4% at 100 mmol/l whereas type 1 phosphorylase phosphatase activity increased only by 24.5% (n = 5). PLB phosphatase activity was enhanced to 155.9±11.7% by 100 mmol/l BDM (n = 5).
It is concluded that the effects of BDM on contractile parameters are accompanied by decreased phosphorylation of the cardiac regulatory proteins TnI and PLB which could in part be due to activation of type 1 or 2A phosphatase activity. Hence, it is suggested that BDM affects the phosphorylation state of TnI and PLB not directly, but via activation of their phosphatases.
Similar content being viewed by others
References
Alpert NR, Blanchard EM, Mulieri LA (1989) Tension-independent heat in rabbit papillary muscle. J Physiol (Lond) 414:433–453
Ahmad Z, Green FJ, Subuhi HS, Watanabe AM (1989) Autonomic regulation of type 1 protein phosphatase in cardiac muscle. J Biol Chem 264:3859–3863
Allen TJA, Chapman RA (1995) The effect of a chemical phosphatase on single calcium channels and the inactivation of whole cell calcium current from isolated guinea-pig ventricular myocytes. Pflügers Arch 430:68–80
Bradford MM (1976) A rapid and sensitive method for quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem 72:248–254
Chapman RA (1993) The effect of oximes on the dihydropyridine-sensitive calcium current of isolated guinea-pig ventricular myocytes. Pflügers Arch 422:325–331
Coulombe A, Lefevre IA, Deroubaix E, Thuringer D, Coraboeuf E (1990) Effect of 2,3-butanedione monoxime on the slow inward and transient outward currents in rat ventricular myocytes. J Mol Cell Cardiol 22:921–932
Dobrowsky RT, Kamibayashi C, Mumby MC, Hannun YA (1993) Ceramide activates heterotrimeric protein phosphatase 2A. J Biol Chem 268:15523–15530
Freyer MW, Neering IR, Stephenson DG (1988) Effects of 2,3-butanedione monoxime on the contractile properties of fast- and slow-twitch rat muscle fibers. J Physiol 407:53–75
Gwathmey JK, Hajjar RJ, Solaro RJ (1991) Effects of 2,3-butanedione monoxime on mammalian myocardium. Circ Res 69:1280–1292
Hescheler J, Kameyama M, Trautwein W, Mieskes G, Söling HD (1987) Regulation of the cardiac calcium channel by protein phosphatases. Eur J Biochem 165:261–266
Hescheler J, Mieskes G, Ruegg JC, Takai A, Trautwein W (1988) Effects of a protein phosphatase inhibitor, okadaic acid, on membrane currents of isolated guinea-pig cardiac myocytes. Pflügers Arch 412:248–252
Horiuti K, Higuchi H, Umazume Y, Konishi M, Okazaki O, Kurihara S (1988) Mechanisms of action of 2,3-butanedione-2-monoxime on contraction of frog skeletal muscle fibers. J Muscle Res Cell Motil 9:156–164
Jones LR (1985) Sarcolemmal enzymes mediating β-adrenergic effects on the heart. In: Bronner FA, Shamoo AE (eds) Current topics in membranes and transport; regulation of calcium transport across muscle membranes. Academic Press, New York, p 11
Kranias EG (1986) Protein phosphorylation and the cardiac sarcoplasmic reticulum. In: Solaro RJ (ed) Protein phosphorylation in heart muscle. CRC Press, Boca Raton, pp 105–128
Luo W, Grupp IL, Harrer J, Ponniah S, Grupp G, Duffy JJ, Doetschman T, Kranias EG (1994) Targeted ablation of the phospholamban gene is associated with markedly enhanced myocardial contractility and loss of β-agonist stimulation. Circ Res 75:401–409
MacDougall LK, Jones LR, Cohen P (1991) Identification of the major protein phosphatases in mammalian cardiac muscle which dephosphorylate phospholamban. Eur J Biochem 196:725–734
Neumann J, Boknik P, Herzig S, Schmitz W, Scholz H, Gupta RC, Watanabe AM (1993) Evidence of physiological functions of protein phosphatases in the heart. Evaluation with okadaic acid. Am J Physiol 265:H257-H266
Neumann J, Boknik P, Bodor GS, Jones LR, Schmitz W, Scholz H (1994a) Effects of adenosine receptor and muscarinic cholinergic receptor agonists on cardiac protein phosphorylation. Influence of pertussis toxin. J Pharmacol Exp Ther 269:1310–1318
Neumann J, Boknik P, Herzig S, Schmitz W, Scholz H, Wiechen K, Zimmermann N (1994b) Biochemical and electrophysiological mechanisms of the positive inotropic effects of calyculin A, a protein phosphatase inhibitor. J Pharmacol Exp Ther 271:535–541
Neumann J, Boknik P, Schmitz W, Scholz H, Zimmermann N (1995a) Comparison of the stereoselective effects of a thiadiazinone derivate on contractile parameters and protein phosphorylation in the mammalian ventricle. J Cardiovasc Pharmacol 25:789–793
Neumann J, Herzig S, Boknik P, Apel M, Kaspareit G, Schmitz W, Scholz H, Tepel M, Zimmermann N (1995b) On the cardiac contractile, biochemical and electrophysiological effects of cantharidin, a phosphatase inhibitor. J Pharmacol Exp Ther 274:530–539
Reddy LG, Jones LR, Cala SE, O'Brian JJ, Tatulian SA, Stokes DL (1995) Functional reconstitution of recombinant phospholamban with rabbit skeletal Ca2+-ATPase. J Biol Chem 270:9390–9397
Sada H, Sada S, Sperelakis N (1985) Effects of diacetyl monoxime (DAM) on slow and fast action potentials of young and old embryonic chick hearts and rabbit hearts. Eur J Pharmacol 112:145–152
Schlüter KD, Schwartz P, Siegmund B, Piper HM (1991) Prevention of the oxygen paradox on hypoxic-reoxygenated hearts. Am J Physiol 261:H416-H423
Stringham JC, Paulsen KL, Southard JH, Fields BL, Belzer FO (1993) Improved myocardial preservation by modification of the University of Wisconsin solution with 2,3-butanedione monoxime and calcium. Trans Proc 25:1625–1626
Wiggins JR, Reiser J, Fitzpatrick DF, Bergey JL (1980) Inotropic actions of diacetyl monoxime in cat ventricular muscle. J Pharmacol Exp Ther 212:217–224
Zhang R, Zhao J, Mandveno A, Potter JD (1995) Cardiac troponin I phosphorylation increases the rate of cardiac muscle relaxation. Circ Res 76:1028–1035
Zimmermann N, Bodor GS, Boknik P, Gams E, Jones LR, Neumann J, Scholz H (1995) Mechanism of the contractile effects of flosequinoxan. Naunyn-Schmiedeberg's Arch Pharmacol 351:385–390
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Zimmermann, N., Boknik, P., Gams, E. et al. Mechanisms of the contractile effects of 2,3-butanedione-monoxime in the mammalian heart. Naunyn-Schmiedeberg's Arch Pharmacol 354, 431–436 (1996). https://doi.org/10.1007/BF00168433
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00168433