Comparative study of non-ionizing and ionizing radiation effect on hydration of winter wheat seeds in metabolic active and inactive states

Although the biological effect of non-ionizing (NIR) and ionizing radiation (IR) on plant seed potential is well documented, the mechanism of this impact is not clear yet. Since cell hydration, a fundamental parameter for determining cell function, is magneto-sensitive, in present work, a comparative study of extremely low frequencies (ELF) electromagnetic field (EMF), ELF EMF-modulated millimeter waves, and radiation exposure effects on winter wheat seeds water absorption and dry mass changes was performed. The seeds were incubated in physiological solutions (PS) for 2 and 72 h. In case of 2-h incubation, the water absorption determined by osmotic gradients between seeds and bathing medium, PS treated by all these factors leads to changes of water absorption. While in case of 72-h incubation (when germination processes are in active state) these impact had reversed character. The obtained data strongly suggest seeds bathing medium as a target through which the biological effects of NIR and IR are realized.     

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

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 H₂O₂ content in PS, as well as on heart contractility, ⁴⁵Ca²⁺ 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 H₂O₂ content-(5 ± 0.9%). The intracardiac perfusion by MV-treated PS increased the amplitudes of heart contractility, which was accompanied by the increasing of ⁴⁵Ca²⁺ 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 H₂O₂ content in the medium, which leads to the elevation of heart muscle contractility in result of activation of cGMP-dependent Na⁺/Ca²⁺ exchange in forward regime.