Homeothermic functions changes with chronic radiofrequency electromagnetic radiation of mobile phone relay-antennae
Résumé
Objectives : we have previously shown that radiofrequency electromagnetic fields (RF-EMF) (type base station antenna) affect sleep of growing rats when this exposure was associated with a thermal stress. We hypothesize that within the thermoneutral zone, the exposed animals were in a process of saving body's energy. Methods : 13 Wistar rats (3 weeks-old) continuously exposed to RF-EMR during six weeks were compared to 11 non-exposed control rats. After surgery, sleep-wakefulness cycle, cortical and peripheral (caudal, Ttail) skin temperatures and food intake were simultaneously measured within 00-06 pm at environmental temperature (24+-1°C) and at the upper limit of thermoneutral zone (31+-1 °C), combined or not with RF exposure. Prazocine was used as adrenergic inhibitor of post-ganglionic fibres of cutaneous microvessels. Patterns of vigilance states were scored by considering their total duration, mean durations and frequencies of episodes. All parameters were tested with ANOVA and post-hoc statistic tests. Results : Ttail was lowered by RF-EMR at 31 °C (-1.21 °C, t55=5.66, p<0.001) for all sleep stages (W: -1.17 °C; SWS: -1.20 °C; PS: -1.25 °C). Cortical temperature did not differ between the two groups (F1,17=0.24, p=0.63). Ttail decreases depend on local vasoconstrictor tone, since it was abolished by prazocine. Peripheral vasoconstriction found in the exposed animals (ascribing by decreases of Ttail) reduces body heat. At 31°C, ingested food quantity during the inactivity period in the day was higher in exposed animals (+1.3 g, t22=4.52, p<0.001) that suggests higher energetic needs in the exposed animals. Conclusion : results show that RF-EMR exposure induces a process of saving energy to preserve homeothermia.