Page 86 - Elektromagnetische Befeldung mit Mobilfunkstrahlen

SUMMARY
7 Summary
Nina Hettenbach:
Effects of chronic exposure to mobile radiation (GSM and UMTS) on the permeability of the blood-brain barrier of rats.
Introduction: This study investigated the effects of chronic exposure to mobile telephony (GSM, UMTS) on the permeability of the blood-brain barrier (bbb) of rats. The integrity of the bbb was measured quantitatively with the unidirectional influx- constant Kin with 14C-saccharose. In order to increase the sensitivity of the investigation compared to other studies, we developed special challenge conditions, which stress the bbb but do not open it.
Method: Three high frequency exposition chambers for GSM 900 MHz-, UMTS 1966 MHz- and sham exposure were set up and three rat generations were continuously (24 h/d) exposed under far field conditions. The field intensity was adjusted to reach a whole body SAR (wb-SAR) of 0.4 W/kg within the animals. This equals the highest admitted wb-SAR which is defined in the German BImSchV for work-related exposure for stationary sources of radiation. The integrity of the bbb was measured after four months of exposure within the generation F0-group1 and F2 and after eleven months of exposure within Generation F0-group2. The quantitative measurement was accomplished by determination of the unidirectional influx- constant Kin with 14C-saccharose within seven defined brain areas of the left and right hemisphere (bulbus olfactorius, cerebellum, medulla oblongata, pons, mesencephalon, diencephalon and cortex). In preliminary tests we developed challenge conditions which stress but do not open the bbb. For this purpose we infused decreasing concentrations of hyperosmolar arabinose dilution into the right A. carotis interna and investigated the highest concentration which does not lead to bbb disruption. In the main tests this concentration was infused into the animals five minutes prior to the measurement of the Kin.
Results: In the preliminary tests bbb disruption was achieved by infusion of 1.6 mol/l arabinose dilution and in some cases after 1.0 mol/l arabinose dilution infusion. Kin-
81