Effects of 1800 MHz and 2100 MHz mobile phone radiation on the blood-brain barrier of New Zealand rabbits.

In the context of potential health risks associated with mobile phone radiation, its effect on the blood-brain barrier (BBB) is of particular relevance. Under normal conditions, this barrier functions so effectively that it significantly limits the absorption of most drugs, posing a major challenge to drug manufacturers. Impairment of the BBB is associated with serious neurological diseases such as Alzheimer's, stroke, and multiple sclerosis. Previous studies have shown that radiofrequency radiation can compromise the BBB, allowing substances to enter the brain that would be excluded by an intact barrier. Understanding the interaction between mobile phone radiation and the BBB is critical because any disruption of BBB integrity could have serious implications for neurological health. The present study investigates the effects of 1800 MHz and 2100 MHz radiation on the BBB using New Zealand rabbits. These animals are commonly used in neurobiological research because of their well-characterized physiology and relatively large brains. The experimental design included non-thermal exposure within the typical range of mobile phone use and a thorough characterization of the exposure setup.

A total of 21 female rabbits were divided into three groups (n = 7 each): cage control, 1800 MHz GSM and 2100 MHz GSM. The animals were exposed once for 38 minutes at a power level of 15 dBm. Exposure was performed in a metal cage to minimize electromagnetic interference. The exposure system allowed real-time monitoring of the emitted radiofrequency power levels, ensuring that the animals were reliably and consistently exposed to the specified power levels. BBB permeability was assessed using Evans Blue dye, which binds to plasma proteins, primarily albumin. The integrity of the BBB is compromised if the dye enters the brain. (Albumin can induce a number of pathological responses in the brain, including disruption of potassium and neurotransmitter homeostasis, editor's note.) For each animal, two brain samples from each hemisphere were collected, homogenized and analyzed spectrometrically at 620 nm.

The researchers observed changes in Evans Blue levels in the brain tissue of the exposed rabbits compared to the unexposed controls. BBB permeability values were increased in both the 1800 MHz and 2100 MHz groups compared to controls, but only the 2100 MHz group showed statistically significant results. A statistically significant difference with a 95% confidence interval was found in absorption at 620 nm for both the left and right hemispheres in the 2100 MHz group compared to the control group.

Even a single exposure under non-thermal conditions with a radiofrequency intensity approximately ten times lower than the "normal value" resulted in increased BBB permeability at 2100 MHz. The exposure setup was designed by the researchers to minimize external interference and to allow for a valid assessment of the effects of radiofrequency radiation. The experimental animals were exposed only to the intended radiofrequency signals, with continuous environmental monitoring to detect any unusual variations. The observed permeability of the BBB may play a role in several neurological diseases such as Alzheimer's, stroke, and multiple sclerosis.

Editor's note:
In particular, the real-time monitoring of radiofrequency exposure and the measurement system are considered high-quality aspects of this study. A sham exposure for the control group would have been desirable in this context, editor's note.) The present study confirms the findings of Sırav & Seyhan, 2016, who also observed increased BBB permeability after a single RF exposure, albeit in rats. BBB impairment has also been documented with long-term RF exposure (Tang et al., 2015). (RH)

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"Increased permeability of the BBB may contribute to Alzheimer's, stroke, and multiple sclerosis."