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Health Effects of Chronic Exposure to Radiation From Mobile Communication
Published in Marko Markov, Mobile Communications and Public Health, 2018
Qin et al. investigated whether chronic exposure to RF (1800 MHz, PD 205 μw/cm2, SAR 0.0405 W/kg) for 2 h/day for 32 days at different zeitgeber time (ZT) points (ZT0, ZT4, ZT8, ZT12, ZT16, and ZT20) affects circadian rhythms of reproductive functional markers in adult male Sprague-Dawley rats (43). Testicular and epididymis tissues were collected and assessed for testosterone levels, daily sperm production and sperm motility, testis marker enzymes gamma-glutamyl transpeptidase (gamma-GT) and acid phosphatase (ACP), cytochrome P450 side-chain cleavage (p450cc) mRNA expression, and steroidogenic acute regulatory protein (StAR) mRNA expression. These measurements revealed pronounced circadian rhythms in sham exposed animals. RF exposure disrupted the circadian rhythms decreasing testosterone levels, lowering daily sperm production and sperm motility, down-regulating activity of gamma-glutamyl transpeptidase (gamma-GT) and ACP, and altering mRNA expression of cytochrome P450 and StAR. The most significant changes were observed in rats exposed to RF at ZT0. The findings indicated potential adverse effects of RF exposure on male reproductive functional markers in terms of daily overall levels and circadian rhythmicity.
Evaluation of glyphosate exposure on testosterone among U.S. adult men
Published in Human and Ecological Risk Assessment: An International Journal, 2023
Frank Glover, Dana Barr, Jasmin Eatman, Wade Muncey, Francesco Del Giudice, Federico Belladelli, Nicolas Seranio, Michael L. Eisenberg
Glyphosate’s primary mechanism of action is via inhibition of 5-enol-pyruvyl-shikimate-3-phosphate synthase (EPSPS), an enzyme that catalyzes the sixth step in the shikimic acid pathway in plants (Malik et al. 1989). By inhibiting this enzyme, glyphosate prevents the biosynthesis of aromatic amino acids resulting in cell death (Kanissery et al. 2019). In the context of hormone dysregulation, glyphosate has been shown to target various components of the hypothalamic-pituitary-gonadal axis and impair testosterone production. For example, glyphosate demonstrates the ability to inhibit the steroidogenic acute regulatory protein (StAR) in vivo and in vitro, an enzyme that regulates testosterone production in the Leydig cells of the testes (Walsh et al. 2000; Zhao et al. 2021). Another study by Wang et al. demonstrated glyphosate’s ability to inhibit testosterone synthesis by inducing reactive oxygen species (ROS) production and activating mitophagy within TM3 cells (mouse Leydig cell lines), effects that were attenuated by addition of antioxidants (Lu et al. 2022). Furthermore, developmental studies by Pham et al. showed that offspring born to pregnant mice who drank glyphosate-treated water had impaired germ cell differentiation, low sperm counts, and low testosterone (Pham et al. 2019; Teleken et al. 2020). Thus, a number of these pathways and mechanisms may be activated in humans following glyphosate exposure and potentially affect testosterone, and future studies are warranted to test these relationships.