The metabolic pathway of 4 Hz mechanical vibration-induced effect on snail heart muscle contractility

摘要

It was shown that the 4 Hz 30 dB mechanical vibration (MV) of physiological solution (PS) had modulation effect on snail heart contractility. However, the nature of metabolic pathway of MV-treated PS-induced effect is not clear yet. It was suggested that the MV-induced modulation of water molecules dissociation leads to the variation of reactive oxygen species' level in cell bathing medium, which could serve as a messenger for switching on the metabolic pathway(s) responsible for modulation of muscle contractility. The aim of present work was to check this hypothesis and to elucidate the metabolic pathway through which the effect of MV-treated PS on heart contractility was realized. For this purpose, the effect of MV on heat fusion periods (HFP) and H_2O_2 content in PS, as well as on heart contractility, ~(45)Ca~(2+) efflux, intracellular levels of cGMP and cAMP, muscle hydration, and ouabain binding were studied. It was shown that MV treatment of PS increased the HFP-(21.33 ± 4%) and decreased the H_2O_2 content-(5 ± 0.9%). The intra-cardiac perfusion by MV-treated PS increased the amplitudes of heart contractility, which was accompanied by the increasing of ~(45)Ca~(2+) efflux (252.4 ± 16%), elevation of cGMP's level (42.05 ± 7%), decreasing of cAMP's level (82.67 ± 7%), increasing of the tissue hydration (18.64 ± 3%), and increasing of the number of ouabain binding sides (25 ± 4%). It was suggested that MV-induced increasing of heart muscle contraction amplitudes is due to the decreases of H_2O_2 content in the medium, which leads to the elevation of heart muscle contractility in result of activation of cGMP-dependent Na~+/Ca~(2+) exchange in forward regime.