Effect of Exposure to 900 MHz GSM Mobile Phone Radiofrequency Radiation on Estrogen Receptor Methylation Status in Colon Cells of Male Sprague Dawley Rats.

BACKGROUND: Over the past several years, the rapidly increasing use of mobile phones has raised global concerns about the biological effects of exposure to radiofrequency (RF) radiation. Numerous studies have shown that exposure to electromagnetic fields (EMFs) can be associated with effects on the nervous, endocrine, immune, cardiovascular, hematopoietic and ocular systems. In spite of genetic diversity, the onset and progression of cancer can be controlled by epigenetic mechanisms such as gene promoter methylation. There are extensive studies on the epigenetic changes of the tumor suppressor genes as well as the identification of methylation biomarkers in colorectal cancer. Some studies have revealed that genetic changes can be induced by exposure to RF radiation. However, whether or not RF radiation is capable of inducing epigenetic alteration has not been clarified yet. To date, no study has been conducted on the effect of radiation on epigenetic alterations in colorectal cancer (CRC). Several studies have also shown that methylation of estrogen receptor α (ERα), MYOD, MGMT, SFRP2 and P16 play an important role in CRC. It can be hypothesized that RF exposure can be a reason for the high incidence of CRC in Iran. This study aimed to investigate whether epigenetic pattern of ERα is susceptible to RF radiation and if RF radiation can induce radioadaptive response as epigenetic changes after receiving the challenge dose (γ-ray). MATERIAL AND METHOD: 40 male Sprague-Dawley rats were divided into 4 equal groups (Group I: exposure to RF radiation of a GSM cell phone for 4 hours and sacrificed after 24 hours; Group II: RF exposure for 4 hours, exposure to Co-60 gamma radiation (3 Gy) after 24 hours and sacrificed after 72 hrs; Group III: only 3Gy gamma radiation; Group 4: control group). DNA from colon tissues was extracted to evaluate the methylation status by methylation specific PCR. RESULTS: Our finding showed that exposure to GSM cell phone RF radiation was capable of altering the pattern of ERα gene methylation compared to that of non-exposed controls. Furthermore, no adaptive response phenomenon was induced in the pattern of ERα gene methylation after exposure to the challenging dose of Co-60 γ-rays. CONCLUSION: It can be concluded that exposure to RF radiation emitted by GSM mobile phones can lead to epigenetic detrimental changes in ERα promoter methylation pattern.

Changes in the gene expression of adiponectin and adiponectin receptors (AdipoR1 and AdipoR2) in ovarian follicular cells of dairy cow at different stages of development.

Adiponectin is one of the most important, recently discovered adipocytokines that acts at various levels to control male and female fertility through central effects on the hypothalamus-pituitary axis or through peripheral effects on the ovary, uterus, and embryo. We studied simultaneous changes in the gene expression pattern of adiponectin and adiponectin receptors 1 and 2 (AdipoR1 and AdipoR2) in granulosa and theca cells, cumulus-oocyte complex, and in corpus luteum in healthy bovine (Bos tarus) follicles at different stages of development. The expression levels of adiponectin, AdipoR1, and AdipoR2 mRNA were lower (P<0.05) in granulosa and cumulus cells in comparison with that in theca cells and oocyte. In contrast with the oocyte, AdipoR1 in granulosa, theca, and luteal cells was expressed (P<0.05) more than AdipoR2. Adiponectin expression increased (P<0.05) in granulosa cells and in cumulus-oocyte complex during follicular development from small to large follicles. Opposite results were observed in theca cells. Expression of adiponectin was highest in the late stages of corpus luteum (CL) regression, whereas lower expression was recorded in active CL (P<0.05). AdipoR1 and AdipoR2 expression increased during the terminal follicular growth in granulosa and theca cells (P<0.05) and during the luteal phase progress in CL. There was positive correlation between adiponectin mRNA level in granulosa cells from large follicles and follicular fluid estradiol concentration (r=0.48, P<0.05) and negative correlation between adiponectin mRNA abundance in theca cells and follicular fluid progesterone concentration (r=-0.44, P<0.05). In conclusion, we found that the physiologic status of the ovary has significant effects on the natural expression patterns of adiponectin and its receptors in follicular and luteal cells of bovine ovary.

Physiological response of dromedary camels to road transportation in relation to circulating levels of cortisol, thyroid hormones and some serum biochemical parameters.

Transportation is often considered as one of the main causes of stress raising considerable interest, both in economic and animal welfare terms. The objective of the current study was to determine physiological response of dromedary camels to road transportation in relation to circulating levels of cortisol, thyroid hormones and some serum biochemical factors during summer conditions. Ten Iranian dromedary camels, five males and five females, were selected for the study. The study was conducted on three consecutive days in August 2008. At first day, blood samples were collected at 08:30 A.M., 09:30 A.M. and 01:30 P.M. to determine any possible variation in individual measurements due to diurnal changes or as a result of food and water deprivation for 5 h. Travel commenced on day 2 at 08:30 A.M. for 5 h, with a total of about 300 km traveled. At second day, blood samples were collected immediately before loading, at 08:30 a.m., after 1 h transport, at 09:30 A.M., and on the end of transportation, after unloading, at 01:30 P.M. Final blood sample was taken 24 h after arrival. In the current study no significant difference was observed in any parameter between sexes at each sampling time. The data related to day before transport had no significant differences between different times except for values obtained for cortisol that at 01:30 P.M. showed a significant decrease in comparison with data at 08:30 and 09:30. Circulating cortisol, T(4), T(3) and fT(4) levels was significantly higher after transportation compared with pre-transport values and returned to basal values within 24 h after transport. Transportation had effects on metabolism as demonstrated by increase in serum concentrations of glucose, NEFA, and urea nitrogen. Serum concentrations of glucose, NEFA, and urea nitrogen returned to basal values in final bleeding at 24 h after transport termination. In the current study transportation had no significant effects on serum concentrations of fT(3), triglycerides, cholesterol, beta-hydroxybutyrate, albumin and total protein. Taken together, the results obtained for short road transportation of dromedary camels showed a strong physiological response and provide some biomarkers for stress detection in this species. Further research to validate these potential biomarkers is necessary.