RESUMO
Indisputable population exposure to widespread electromagnetic fields, has grown concerns over the probable health effects of these fields. The present study was aimed to examine the possible effects of 50 Hz extremely low frequency electromagnetic field [ELF-EMF] exposure on the number and quality of mice blastocysts. In present study, 66 NMRI pregnant females divided into two treated and non-treated groups. The treated group exposed to ELF-EMF [50 Hz and 6×10[-3] T]. Subsequently, embryos were collected by flushing the uterine horn and Fallopian tubes on the day 3 of gestation. Number of trophoectoderm [TE] and Inner Cell Mass [ICM] cells in blastocysts were determined after differential nuclei staining using a modified method. Furthermore, number of all flushed blastocysts calculated in each group. There was no significant difference in mean number of blastocysts in treated [6.64 +/- 1.34] and none treated [8.22 +/- 1.59] groups. In treated group, there were significant decreased in total cell number of blastocysts [p=0.000], number of ICM cells [p=0.000], and number of TE cells [p=0.001] whereas the ratio of ICM/TE cells increased [p=0.002]. The data indicate that ELF-EMF is able to affect cellular composition of blastocysts, but it can't omit total volume of blastocysts
RESUMO
Because of the necessity of more effective treatments for the nervous system injuries and considering the role of survivin in cellular proliferation and apoptotic cell death, we have monitored survivin gene expression changes during the course of regeneration in injured sciatic nerves and also L4-L6 segments of spinal cord. We used adult male NMRI mice as a model. After anesthetizing the animals, the right sciatic nerve was transected and at the indicated times [3, 6, 12, 24, 48, 96 and 144 hours] the animals were sacrificed and both distal and proximal segments of the transected sciatic nerve, intact left sciatic nerve and L4-L6 segments of spinal cord were dissected. The total RNA was extracted from each sampled and semi-quantitative RT-PCR with specific primers for survivin and also beta2-microglobulin genes, as an internal control, was performed. To determine cellular distribution of survivin protein, 6 days [144 hours] after the axotomy, survivin protein expression was evaluated using immunohistochemistry technique. Our results demonstrated the expression of both survivin140 and survivin40 in distal and proximal segments of sciatic nerve with different intensity, where the expression of survivin140 was higher than survivin40. In spinal cord segments, only survivin140 expression was detected. In immunohistochemistry analysis of spinal cord segments, both the nuclear and cytoplasmic distribution of survivin protein was observed. In contrast, survivin protein has not been detected in either distal or proximal segments of sciatic nerve. Our data suggest that survivin is differentially expressed and spliced during the course of regeneration in damaged nerve and spinal cord. It seems that manipulation of expression and/or splicing of survivin could potentially affect the process of regeneration in nerve and/or spinal cord injuries