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9 postsFilters: tag: sprague-dawley-rats Clear
Development and Testing of a Novel Whole-body Exposure System for Investigative Studies of Radiofrequency Radiation in Rodents (NIEHS)
This NIEHS report describes the development and testing of a flexible whole-body radiofrequency radiation exposure system for rats and mice using updated signals relevant to wireless technologies. In 5-day studies with CDMA- and GSM-modulated signals, no visible behavioral responses were observed and comet assays reported no DNA damage in multiple tissues. The report notes technical challenges, particularly difficulty obtaining reliable body temperature measurements during exposure, and positions the system as a prototype for future mechanistic toxicology studies.
NTP Lite: The Japan-Korea Collaborative RF Exposure Toxicity Project [Health Matters]
This magazine article reviews the Japan-Korea "NTP Lite" RF animal toxicity collaboration and its relationship to prior NTP (2018) and Ramazzini Institute reports of RF-associated tumors in male rats. It notes NTP Lite used a single whole-body SAR of 4 W/kg and completed a two-year exposure phase in 2022, but final reporting is delayed with histopathology and genotoxicity work ongoing. The author highlights protocol harmonization across labs while raising concerns about unexplained animal deaths and physiological differences in exposed groups, and frames the broader evidence as supportive of RF-related cancer risk in laboratory animals.
Time-Dependence Effect of 2.45 GHz RF-EMR Exposure on Male Reproductive Hormones and LHCGR
This animal study exposed male Sprague Dawley rats to 2.45 GHz Wi-Fi for varying daily durations over eight weeks and assessed reproductive hormones and LHCGR expression. Serum LH and testosterone did not differ significantly from controls, but LHCGR mRNA increased with longer exposure and LHCGR protein showed decreases with shorter exposures with partial improvement at 24 hours/day. The findings suggest molecular alterations in testicular tissue despite stable systemic hormone levels.
Simultaneous 4G and 5G EMF Exposure and Field Uniformity in a Reverberation Chamber for Animal Studies
This engineering study describes the design and validation of a reverberation chamber intended for large-scale animal carcinogenicity research with RF EMF relevant to 4G/5G. E-field uniformity was tested under four loading scenarios, including setups with 80 Sprague-Dawley rats. The chamber achieved better than 1.36 dB E-field uniformity across scenarios, and the authors report a method to predict composite E-field intensity for simultaneous multi-frequency exposures.
Characterization of the Core Temperature Response of Free-Moving Rats to 1.95 GHz Electromagnetic Fields
This animal study measured core body temperature in free-moving male and female Sprague Dawley rats during and after 3-hour exposure to 1.95 GHz RF-EMF at multiple whole-body average SAR levels. A measurable thermal response was reported at 4 W/kg, while lower SAR conditions showed smaller or no significant temperature increases. The authors note that temperature dropped quickly after exposure ended, implying post-exposure measurements may underestimate peak heating.
Effects of non-ionizing radiation on the thyroid gland in rats
This animal study exposed Sprague-Dawley rats (including pregnant females and offspring) to 2.45 GHz Wi-Fi or mobile jammer radiation for 2 hours daily over two weeks and assessed thyroid hormones and thyroid histology. The abstract reports significant changes in T4 in exposed adult males and significant differences in T3 among male offspring exposed to jammer radiation. Histopathology reportedly showed disrupted thyroid follicular structure in exposed rats. The authors conclude these findings support a potential link between non-ionizing radiation exposure and altered thyroid endocrine and histological parameters.
Histomorphometry and Sperm Quality in Male Rats Exposed to 2.45 GHz Wi-Fi
This animal study exposed adult male rats to 2.45 GHz Wi‑Fi from an active router for 4 or 24 hours daily over eight weeks and assessed reproductive organ histology and sperm parameters. The authors report histological changes in testes and epididymis, multifocal atypical hyperplasia in seminal vesicles, reduced seminiferous tubule diameter, and reduced spermatogenesis index in exposed groups. Sperm concentration decreased in both exposed groups, motility decreased in the 4-hour group, and viability increased in the 24-hour group, leading to an overall interpretation of potential reproductive risk under the studied conditions.
Toxicology and carcinogenesis studies in Sprague Dawley (Hsd:Sprague Dawley SD) rats exposed to whole-body radio frequency radiation at a frequency (900 MHz) and modulations (GSM and CDMA) used by cell phones
This National Toxicology Program technical report describes 900 MHz whole-body RFR exposures (GSM and CDMA) in male and female Sprague Dawley rats from in utero through up to 2 years. The report concludes clear evidence of carcinogenic activity in males for both modulations based on malignant schwannoma of the heart, with malignant glioma of the brain also reported as related to exposure. In females, the report concludes equivocal evidence of carcinogenic activity for both modulations based on selected tumor outcomes, and genetic toxicology findings were mixed with some comet assay increases/equivocal results but negative micronucleus assays.
Effect of Exposure to 900 MHz GSM Mobile Phone Radiofrequency Radiation on Estrogen Receptor Methylation Status in Colon Cells of Male Sprague Dawley Rats
This animal study exposed male Sprague-Dawley rats to 900 MHz GSM mobile phone RF radiation for 4 hours and assessed ERα promoter methylation in colon tissue. The authors report altered ERα methylation patterns versus controls after RF exposure. They also report no radioadaptive response in ERα methylation following a subsequent 3 Gy Co-60 gamma challenge.