Effects of 50 Hz magnetic field on cell cycle kinetics and the colony forming ability of budding yeast exposed to ultraviolet radiation

Abstract

To investigate the effects of extremely low frequency magnetic fields on ultraviolet radiation (UV) exposed budding yeast, haploid yeast (Saccharomyces cerevisiae) cells of the strain SEy2101a were exposed to 50 Hz sine wave magnetic field (MF) of 120 microT with simultaneous exposure to UV radiation. Most of the UV energy was in the UVB range (280-320 nm). The biologically weighted (CIE action spectrum) dose level for the UV radiation was 175 J/m2. We examined whether 50 Hz MF affected the ability of UV irradiated yeast cells to form colonies (Colony Forming Units, CFUs). In addition, the effect of coexposure on cell cycle kinetics was investigated. Although the significant effect of MF on the cell cycle phases of UV exposed yeast cells was seen only at one time point, the overall results showed that MF exposure may influence the cell cycle kinetics at the first cycle after UV irradiation. The effect of our particular MF exposure on the colony forming ability of the UV irradiated yeast cells was statistically significant 420 min after UV irradiation. Moreover, at 240, 360, and 420 min after UV irradiation, there were fewer CFUs in every experiment in (UV+MF) exposed populations than in only UV exposed yeast populations. These results could indicate that MF exposure in conjunction with UV may have some effects on yeast cell survival or growth.

No influence of magnetic fields on cell cycle progression using conditions relevant for patients during MRI

“…Liboff et al [1984] observed an increased DNA synthesis of human fibroblasts after exposure to 2.3 Â 10 À6 -5.6 Â 10 À4 T at 4 kHz. An influence of low frequency MFs on ultraviolet radiation exposed yeast cells was reported by Markkanen et al [2001]. Exposure of yeast cells exposed to 120 mT, 50 Hz, influenced cell cycle phases at the first cell cycle after UV irradiation.…”

Apoptosis induced by ultraviolet radiation is enhanced by amplitude modulated radiofrequency radiation in mutant yeast cells

“…In our previous studies, we have observed that 50 Hz magnetic fields may affect yeast cell survival or growth and cell cycle [Markkanen et al, 2001]. Gos and colleagues exposed growing and resting yeast cells to 900 MHz GSM modulated RF field at SAR levels of 0.13 and 1.3 W/kg [Gos et al, 2000].…”

“…After that, the Petri dishes were placed on special exposure system in which the UV lamp is underneath the Petri dishes (described in detail in Markkanen et al [2001]). The plastic material (high density polyethylene) of the Petri dishes reduced the UV radiation intensity only slightly at wavelenghts from 280 to 320 nm (UVB).…”

Mechanisms of the target response to magnetic fields and their correlation with the biological complexity

“…1 and 2a, b). The changes of Friend erythroleukemia (FL) proliferation, following the addition or deprivation of MFs (Eremenko et al 1997), were consistent with the alteration of the onset of S-phase seen after a 50 Hz MF exposure of normal human fibroblasts (Cridland et al 1999) and with variation of growth and colony forming ability after exposure of budding yeast to 50 Hz MF (Markkanen et al 2001).…”