Efeito do diidrocloreto de 2, 2-azobis (2-metilpropionamidina) sobre músculo liso de traquéia de rato
Gomes, Maria Diana MoreiraNeves, Dieniffer PeixotoRodrigues, Karilane Maria SilvinoTeixeira, Ana Carolina CardosoLima, Felipe CrescêncioCardoso José Henrique, Leal
The effects of 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH), an inducer agent of free radicals (peroxyl radical) formation, on the rat tracheal smooth muscle. The experiments were performed on tracheal ring preparations maintained in aerated modified Tyrode solution, in pH 7,4 at 37 °C. The force developed by the tracheal smooth muscle was measured by the isometric force transducer connected to a computerized system. On contractions induced by acetylcholine (10 M), AAPH presented a biphasic effect: contraction potentiation at low concentration on intact and denuded epithelium preparations (CE50 = 0,8776 0,415 mM and CE50 = 0,3338 0,343 mM, respectively); and contraction inhibition at high concentration on intact and denuded epithelium preparations (CE50 = 81,55 62 4,284 mM and CE50 = 57,7786 8,607 mM, respectively). On electromechanic coupling, AAPH inhibited contractions induced by KCl (60 mM) on intact and denuded epithelium preparations (CE50 = 57,4037 4,652 mM and CE50 = 32,9650 2,652 mM, respectively). In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. In conclusion, AAPH presented a concentration-dependent biphasic effect (pontentiation and inhibition) on pharmacomechanic coupling while it was able to only inhibit the electromechanic coupling. Comparing the present data with those available in literature for H2O2, we can suggest that these observed effects are not specific for AAPH, but they are derived from the free radicals induced by AAPH.
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