Effect of GSM-900 and -1800 signals on the skin of hairless rats. III: Expression of heat shock proteins.

Sanchez S, Masuda H, Ruffié G, De Gannes FP, Billaudel B, Haro E, Lévêque P, Lagroye I, Veyret B.

Int J Radiat Biol. Sep 8;:1-8, 2007

[Epub ahead of print]

Purpose: We previously reported the inability of Global System for Mobile communication (GSM) signals at 900 (GSM-900) and 1800 (GSM-1800) MegaHertz (MHz) to induce morphological and physiological changes in epidermis of Hairless rats.

The present work aimed at investigating heat shock proteins (HSP) expression - as a cellular stress marker - in the skin of Hairless rats exposed to GSM-900 and -1800 signals.

Materials and methods: We studied the expression of the Heat-shock cognate (Hsc) 70, and the inducible forms of the Heat-shock proteins (Hsp) 25 and 70. Rat skin was locally exposed using loop antenna and restrain rockets to test several Specific Absorption Rates (SAR) and exposure durations: (i) single exposure: 2 hours at 0 and 5 W/kg; (ii) repeated exposure: 2 hours per day, 5 days per week, for 12 weeks, at 0, 2.5, and 5 W/kg. HSP expression was detected on skin slices using immunolabeling in the epidermal area.

Results: Our data indicated that neither single nor repeated exposures altered HSP expression in rat skin, irrespective of the GSM signal or SAR considered.

Conclusions: Under our experimental conditions (local SAR <5 W/kg), there was no evidence that GSM signals alter HSP expression in rat skin.