Cell hydration as a biomarker for estimation of biological effects of nonionizing radiation on cells and organisms

Abstract

"Changes in cell hydration" have been hypothesized as an input signal for intracellular metabolic cascade responsible for biological effects of nonionizing radiation (NIR). To test this hypothesis a comparative study on the impacts of different temperature and NIR (infrasound frequency mechanical vibration (MV), static magnetic field (SMF), extremely low frequency electromagnetic field (ELF EMF), and microwave (MW)) pretreated water on the hydration of barley seeds in its dormant and germination periods was performed. In dormant state temperature sensitivity (Q 10) of seed hydration in distilled water (DW) was less than 2, and it was nonsensitive to NIR treated DW, whereas during the germination period (48-72 hours) seeds hydration exhibited temperature sensitivity Q 10 > 2 and higher sensitivity to NIR treated DW. Obtained data allow us to suggest that the metabolic driving of intracellular water dynamics accompanied by hydrogen bonding and breaking is more sensitive to NIR-induced water structure changes in seed bathing aqua medium than the simple thermodynamic processes such as osmotic gradient driven water absorption by seeds in dormant state. Therefore, cell hydration is suggested to be a universal and extrasensitive biomarker for detection of biological effects of NIR on cells and organisms.

Figure 1

Protocol of experiments of the study of Sham and NIR treated DW effects on seed hydration at the end of 2, 24, 48, and 72 hours of incubation in DW.

Figure 2

Setup for treatment of DW by NIR: (1) glass test tube with 500 cm³ 10 mL; (2) platinum electrodes; (3) mobile part of the vibrator; (3′) motionless part of the vibrator; (4) coil; (5) device for the measurement of DW SEC (conductometer); (6) generator of sinusoid vibration; (7) low-noise amplifier; (8) the switch (has 2 positions: I and II, I: EMF and MV and II: EMF); (9) personal computer; (10) generator of a constant field (SMF).

Figure 3

Time-dependent changes in seed hydration during 72 hours of incubation in nontreated (“C” = Sham) DW in cold (4°C; (A) clear symbol) and warm (20°C; (B) dark symbol) conditions. S = initial reading at 5 minutes after the start of the incubation. In the present and the following figures: “C” means Control-Sham. The time (in hours) of seeds incubation on abscissa and the value of seed hydration (mg of H₂O for 1 mg of dry weight) on ordinate are presented. The results are shown as mean ± SEM (n = 300) from three independent experiments, 100 seeds from each experiment. ^∗ P < 0.05, compared with Sham, ^∗∗ P < 0.01.

Figure 4

Barley seeds germination at the end of 72 hours, which were 15 minutes preincubated in Sham (control) (a) and 15 Hz MV treated (b) DW.

Figure 5

Time-dependent changes in seed hydration during 72 hours of incubation in MV (15 Hz; 30 dB) treated (gray column) and nontreated Sham (clear column) DW in cold (4°C; clear/grey with no pattern markings) and warm (20°C; clear/grey with horizontal pattern markings) conditions. The time (in hours) of seeds incubation on abscissa and the value of seed hydration (mg of H₂O for 1 mg of dry weight) on ordinate are presented. The results are shown as mean ± SEM (n = 300) from three independent experiments, 100 seeds from each experiment. ^∗ P < 0.05, compared with Sham, ^∗∗ P < 0.01.

Figure 6

Time-dependent changes in seed hydration during 72 hours of incubation in SMF (2.5 mT) treated (gray column) and nontreated Sham (clear column) DW in cold (4°C; clear/grey with no pattern markings) and warm (20°C clear/grey with horizontal pattern markings) conditions. The time (in hours) of seeds incubation on abscissa and the value of seed hydration (mg of H₂O for 1 mg of dry weight) on ordinate are presented. The results are shown as mean ± SEM (n = 300) from three independent experiments, 100 seeds from each experiment. ^∗ P < 0.05, compared with Sham, ^∗∗ P < 0.01.

Figure 7

Time-dependent changes in seed hydration during 72 hours of incubation in ELF EMF (15 Hz) treated (gray column) and nontreated Sham (clear column) DW in cold (4°C; clear/grey with no pattern markings) and warm (20°C; clear/grey with horizontal pattern markings) conditions. The time (in hours) of seeds incubation on abscissa and the value of seed hydration (mg of H₂O for 1 mg of dry weight) on ordinate are presented. The results are shown as mean ± SEM (n = 300) from three independent experiments, 100 seeds from each experiment. ^∗ P < 0.05, compared with Sham, ^∗∗ P < 0.01.

Figure 8

Time-dependent changes in seed hydration during 72 hours of incubation in MW treated (gray column) and nontreated Sham (clear column) DW in cold (4°C; clear/grey with no pattern markings) and warm (20°C; clear/grey with horizontal pattern markings) conditions. The time (in hours) of seeds incubation on abscissa and the value of seed hydration (mg of H₂O for 1 mg of dry weight) on ordinate are presented. The results are shown as mean ± SEM (n = 300) from three independent experiments, 100 seeds from each experiment. ^∗ P < 0.05, compared with Sham, ^∗∗ P < 0.01.