Actas de congresos
Effects Of Manganese Ions In The Neuromuscular Junction
Registro en:
Revista Brasileira De Toxicologia. , v. 18, n. 1, p. 17 - 26, 2005.
14152983
2-s2.0-27844538722
Autor
Oshima-Franco Y.
Leite G.B.
Dal Belo C.A.
Rodrigues-Simioni L.
Institución
Resumen
The neurotoxic effects of manganese occurred mainly from its inhalation are well described in the literature. In this study we have been demonstrated the potent and reversible effect of manganese ions (Mn 2+) on neuromuscular transmission using conventional myographic technique. The Mn 2+ mechanism which causes reversible blockade at neuromuscular junctions was investigated in isolated mouse phrenic nerve-diaphragm (PND) preparations. As much Mn 2+ 0.9 mM as Mn 2+ 1.8 mM produced rapid neuromuscular blockade (50% in < 4 min), but only the lower concentration reversed spontaneously. The use of d-tubocurarine (5.8 μM), 3,4-diaminopyridine (3,4-DAP, 0.09 mM) and dantrolene (10 μM) excluded the involvement of nicotinic receptors, K + channels and ryanodine receptors, respectively, as the potential target for this ion. Manganese acts as an early competitive antagonist and after as an agonist of Ca 2+, indicating that this ion may probably act via Ca 2+ channels. 18 1 17 26 Bülbring, E., Observation on the isolated phrenic nerve diaphragm preparation of the rat (1946) Br. J. Pharmacol., London, 1, pp. 38-61 Crossgrove, J., Zheng, W., Manganese toxicity upon overexposure (2004) NMR Biomed. Chichester, 17 (8), pp. 544-553 Dobson, A.W., Erikson, K.M., Aschner, M., Manganese neurotoxicity (2004) Ann. N. Y. Acad. Sci., New York, 1012 (3), pp. 115-128 Dorman, D.C., McManus, B.E., Parkinson, C.U., Manuel, C.A., McElveen, A.M., Everitt, J.I., Nasal toxicity of manganese sulfate and manganese phosphate in young male rats following subchronic (13-week) inhalation exposure (2004) Inhal. Toxicol., Philadelphia, 16 (6-7), pp. 481-488 Heluany, N.F., Homsi-Brandeburgo, M.I., Giglio, J.R., Prado-Franceschi, J., Rodrigues-Simioni, L., Effects induced by bothropstoxin, a component from Bothrops jararacussu snake venom, on mouse and chick muscle preparations (1992) Toxicon, Exeter, 30 (10), pp. 1203-1210 Meiri, U., (1975) Divalent Ions and Synaptic Transmission at the Neuromuscular Junction, , Ph.D. Thesis. Hebrew University, Jerusalem Meiri, U., Rahamimoff, R., Activation of transmitter release by strontium and calcium ions at the neuromuscular junction (1971) J. Physiol., Cambridge, 15, pp. 709-726 Meiri, U., Rahamimoff, R., Neuromuscular transmission: Inhibition by manganese ions (1972) Science, Cambridge, 176 (32), pp. 308-309 Miledi, R., Strontium as a substitute for calcium in the process of transmitter release at the neuromuscular junction (1966) Nature, Cambridge, 212, pp. 1233-1234 Oshima-Franco, Y., Leite, G.B., Belo, C.A., Hyslop, S., Prado-Franceschi, J., Cintra, A.C., Giglio, J.R., Rodrigues-Simioni, L., The presynaptic activity of bothropstoxin-I, a myotoxin from Bothrops jararacussu snake venom (2004) Basic Clin. Pharmacol. Toxicol., Oxford, 95 (4), pp. 175-182 Rasgado-Flores, H., Sanches-Armass, S., Blaustein, M.P., Nachshen, D.A., Strontium, barium, and manganese metabolism in isolated presynaptic nerve terminals (1987) Am. J. Physiol., Bethesda, 252 (6 PART 1), pp. C604-C610 Soares, A.M., Oshima-Franco, Y., Vieira, C.A., Leite, G.B., Fletcher, I.E., Jiang, M.-S., Cintra, A.C.O., Rodrigues-Simioni, L., Mn 2+ ions reduce the enzymatic and pharmacological activities of bothropstoxin-I, a myotoxic Lys49 phospholipase A 2 homologue from Bothrops jararacussu snake venom (2002) Int. J. Biochem. Cell Biol., Oxford, 34 (6), pp. 668-677 Takeda, A., Essential trace metals and brain function (2004) Yakugaku Zasshi., Tokyo, 124 (9), pp. 577-585