Modest increase in temperature affects ODC activity in L929 cells: low-level radiofrequency radiation does not,

Hoyto A, Sihvonen AP, Alhonen L, Juutilainen J, Naarala J

Radiat Environ Biophys, Jul 19; 2006

[Epub ahead of print]

The effects of low-level radiofrequency (RF) radiation and elevated temperature on ornithine decarboxylase (ODC) activity were investigated in murine L929 fibroblasts.

The cells were exposed at 900 MHz either to a pulse-modulated (pulse frequency 217 Hz; GSM-type modulation) or a continuous wave signal at specific absorption rate (SAR) levels of 0.2 W kg(-1) (0.1-0.3 W kg(-1)) and 0.4 W kg(-1) (0.3-0.5 W kg(-1)) for 2, 8, or 24 h. RF radiation did not affect cellular ODC activity. However, a slight increase in temperature (0.8-0.9 degrees C) in the exposure system lead to decreased ODC activity in cell cultures. This was verified by tests in which cells were exposed to different temperatures in incubators. The results show that ODC activity is sensitive to small temperature differences in cell cultures. Hence, a precise temperature control in cellular ODC activity studies is needed.