Cellular redox disruption and apoptosis: Differential effects of RFR frequencies on Leydig cells.

Leydig cells are essential for maintaining spermatogenesis because they produce testosterone. There is growing evidence that radiofrequency (RF) radiation negatively affects male fertility. This evidence suggests that oxidative stress and apoptosis are key pathological mechanisms. This study aims to conduct a systematic investigation of the frequency-specific effects of RF radiation on the redox balance and apoptosis of Leydig cells.

The study used the murine TM3 Leydig cell line. The cells were exposed to three types of RF radiation: a 4G mobile phone (Xiaomi Note 7, 2318 GHz), an 1800 MHz signal generator (continuous wave), and a 2450 MHz signal generator (continuous wave). The exposure durations for the cell cultures were 15, 30, 45, 60, 90, and 120 minutes. (See "Radiofrequency radiation-induced changes in Leydig cell function" in EREP 02/26; the basic study design is identical; editor’s note.) Temperature effects were ruled out. Nitric oxide and superoxide were quantified as markers of oxidative stress. Cell apoptosis was determined by Annexin V-FITC/propidium iodide double staining, followed by flow cytometry to detect early and late apoptotic fractions. All experiments were independently repeated three times (n = 3). Statistical analysis included one- and two-way ANOVA with a Dunnett’s multiple comparisons test.

The nitric oxide concentration exhibited a frequency-specific, biphasic pattern. When the exposure source was a mobile phone, a statistically significant increase was observed after 30 and 45 minutes, followed by a transient decrease and another statistically significant increase after 120 minutes. However, when exposed to an 1800 and 2450 MHz signal generator, hardly any significant increases in nitric oxide levels were observed. Instead, significant decreases were noted after 15 minutes (in both conditions), after 30 minutes (in the 1800 MHz condition), and after 90 minutes (in the 1800 MHz condition). Intracellular superoxide levels rose progressively under all three conditions. Exposure to a mobile phone or 2450 MHz resulted in earlier and more pronounced accumulation than exposure to 1800 MHz. A progressive, statistically significant increase in total apoptotic cells was observed for all exposure sources and frequencies. Most cells exposed to mobile phones or 2450 MHz underwent early apoptosis, while most cells exposed to 1800 MHz underwent late apoptosis.

This study suggests that RF radiation from various sources and frequencies can disrupt the redox balance and induce apoptosis in TM3 Leydig cells. These frequency- and source-dependent differences may point to distinct signaling pathways through which RF radiation exerts its effects. The biphasic pattern may indicate an adaptive response followed by the exhaustion of protective mechanisms. As potential underlying mechanisms, the authors discuss the release of mitochondrial reactive oxygen species (ROS), subsequent peroxynitrite formation, lipid peroxidation, and activation of apoptotic cascades.

Editor’s note:

This issue of the ElektrosmogReport also discusses the "sister study" of this research group (see below), which is convincing due to the study design described in the accompanying review. The observations exhibit a high degree of consistency regarding the mechanistic basis (oxidative stress/apoptosis) and biological effect (reduced testosterone production). The stronger biological effect of higher or modulated frequencies (mobile phone) correlates with the described patterns of the redox and apoptosis systems. One limitation is that, although the authors identified this as a possible mechanism, they did not examine mitochondrial functional parameters (membrane potential, ATP production, and cytochrome C release). Furthermore, the exposure setup and dosimetry were not described in detail, so one must rely on the findings from the "sister study." (RH)