Thursday, December 04, 2014

Analysis of rat testicular proteome following 30-day exposure to 900 MHz electromagnetic field radiation

Analysis of rat testicular proteome following 30-day exposure to 900 MHz electromagnetic field radiation

Sepehrimanesh M, Kazemipour N, Saeb M, Nazifi S. Analysis of rat testicular proteome following 30-day exposure to 900 MHz electromagnetic field radiation. Electrophoresis. 2014 Dec;35(23):3331-8. doi: 10.1002/elps.201400273. Epub 2014 Oct 18.


The use of electromagnetic field (EMF) generating apparatuses such as cell phones is increasing, and has caused an interest in the investigations of its effects on human health.

We analyzed proteome in preparations from the whole testis in adult male Sprague-Dawley rats that were exposed to 900 MHz EMF radiation for 1, 2, or 4 h/day for 30 consecutive days, simulating a range of possible human cell phone use. Subjects were sacrificed immediately after the end of the experiment and testes fractions were solubilized and separated via high-resolution 2D electrophoresis, and gel patterns were scanned, digitized, and processed.

Thirteen proteins, which were found only in sham or in exposure groups, were identified by MALDI-TOF/TOF-MS. Among them, heat shock proteins, superoxide dismutase, peroxiredoxin-1, and other proteins related to misfolding of proteins and/or stress were identified.

These results demonstrate significant effects of radio frequency modulated EMFs exposure on proteome, particularly in protein species in the rodent testis, and suggest that a 30-day exposure to EMF radiation induces nonthermal stress in testicular tissue. The functional implication of the identified proteins was discussed.

Rats were allocated randomly into four equal independent groups, five of which were sham-exposed (without RF-EMF), 15 of which—according to time of exposure to RF-EMF (1, 2, and 4 h)— were divided into three subgroups (short, moderate, and long-time exposure), five per group. During RF-EMF exposure, each five freely moving rats were kept in a pure (i.e. lacking any metal fittings) transparent polycarbonate cage of 42 cm × 26.5 cm × 15 cm, which was near the antenna. Exposure at 900 MHz with the average power density of 86 mW/cm2 (22.8–146.8 mW/cm2) and an average whole body specific absorption rate of 0.19–1.22 W/kg was applied to freely moving animals for 30 consecutive days. These specific absorption rate values are only rough estimates and cannot be stressed exactly. For further details about exposure conditions, see [3] and [9].

In conclusion, in this study we demonstrated differential proteome pattern in rat testes in response to 900 MHz exposure by using 2DE/SNS/MS. Coupling of 2DE with SNS is more popular than other electrophoretic methods such as 2D difference gel electrophoresis due to its simplicity, high sensitivity, and no need of expensive and complicated hardware. Most identified proteins were related to the oxidative stress, HSPs, cytoskeleton, and metabolism. We proposed mechanisms of reproductive side effects of RF-EMF radiation in rat as a model for human studies. High-throughput performance techniques are needed to identify other proteins. On the other hand, we identified some altered protein profiles that were altered in response to RF-EMF and were important in the cytoskeleton and oxidative stress. This work is a preliminary study and further and complementary studies may be necessary for confirmation of these results using other methods such as Western blotting, immunohistochemistry, and/or real-time PCR.


Impact of 900 MHz electromagnetic field exposure on main male reproductive hormone levels: a Rattus norvegicus model

Sepehrimanesh M, Saeb M, Nazifi S, Kazemipour N, Jelodar G, Saeb S. Impact of 900 MHz electromagnetic field exposure on main male reproductive hormone levels: a Rattus norvegicus model.  Int J Biometeorol. 2014 Sep;58(7):1657-63. doi: 10.1007/s00484-013-0771-7. Epub 2013 Dec 20.


This work analyzes the effects of radiofrequency-electromagnetic field (RF-EMF) exposure on the reproductive system of male rats, assessed by measuring circulating levels of FSH, LH, inhibin B, activin B, prolactin, and testosterone.

Twenty adult male Sprague-Dawley rats (180 ± 10 g) were exposed to 900 MHz RF-EMF in four equal separated groups. The duration of exposure was 1, 2, and 4 h/day over a period of 30 days and sham-exposed animals were kept under the same environmental conditions as the exposed group except with no RF-EMF exposure. Before the exposure, at 15 and 30 days of exposure, determination of the above-mentioned hormone levels was performed using ELISA.

At the end of the experiment, FSH and LH values of the long time exposure (LTE) group were significantly higher than the sham-exposed group (p < 0.05). Serum activin B and prolactin in the LTE group showed significant increase and inhibin B showed significant decrease than sham and short time exposed (STE) groups after 30 days RF-EMF exposure (p < 0.05). Also, a significant decrease in serum testosterone levels in the LTE group was found compared to short and moderate time exposed (MTE) groups after 30 days RF-EMF exposure (p < 0.05).

Results suggest that reproductive hormone levels are disturbed as a result of RF-EMF exposure and it may possibly affect reproductive functions. However, testosterone and inhibin B concentrations as a fertility marker and spermatogenesis were decreased significantly.

In conclusion, we have described the presence of hormonal changes in the rat sera after exposure to RF-EMF radiation. The fact that many men carry their cell phones in a trouser pocket or clipped to their belts at the waist is important. This technology exposes the testes to cell phone radiation. Based on our in vitro results, we can speculate that using of continuous wave similar to basic GSM at 900 MHz may cause deterioration of reproductive function through hormonal changes. Although the physiological significance of these changes remains to be clarified, it seems plausible that EMF radiation may have important effects in almost all aspects of hormonal regulation in the male reproductive system. Nevertheless, evaluating the effects of a GSM-modulated signal on reproductive hormone changes require further complementary studies.


Joel M. Moskowitz, Ph.D., Director
Center for Family and Community Health
School of Public Health
University of California, Berkeley

Electromagnetic Radiation Safety

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