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Introduction: Sodium arsenite is an environmental pollutant which its amounts in industrial cities are more than other places because of its use in chemical industry. Human populations are exposed to this chemical compound through food, soil, air and water which has toxic and histopathological effects on different body organs including kidney. The aim of this investigation is to study the quantitative histopathological effects of sodium arsenite on the kidney structure of rats. Materials and Methods: 12 male Wistar rats with mean body weight of 200±20 g were randomly divided into 2 groups (n=6). One treated with sodium arsenite (8 mg/kg/day in drinking water) and the other one (the control group) received drinking water only. 2 months after treatment the rats were weighed, anesthetized with ether and dissected. The left kidney was taken out, cleaned, weighed and then fixed in 10% formaldehyde solution. After obtaining 1mm thick slices, tissue processing was carried out, then 5µm thick sections were prepared and stained using H&E method. Slides were finally studied stereologically and data was statistically analyzed using paired sampled t-test and the means were considered significantly different at p<0.05. Results: The results of this investigation indicated significant reduction in the total mean volume of kidney (p<0.001), cortex (p<0.001), and medulla (p<0.003) in sodium arsenite treated group compared to the control rats. The mean volume of tubules and interstitial tissue as components of cortex reduced significantly compared to the control group (p<0.003).The mean volume of glomeruli and Bowman's capsule was significantly reduced in treated group (p<0.001), while the other components did not show a significant reduction in volume. A significant reduction was also found in the kidney (p<0.002) and the body weight (p<0. 01) in the treated group compared to the control ones at the end of the experiment. Conclusion: It was concluded that exposure to sodium arsenite leads to histopathological changes in kidney structure, however more studies are needed to determine the effects of these structural changes on the kidney function.

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Background: One of the best examples of epimorphic regeneration in the mammals is the formation of new tissues formed from blastema in holes punched in the ears of rabbits. The aim of this research is to investigate speed and percentage of regeneration in different geometrical shaped holes and different regions of rabbit's ear. Methods and Materials: In this experimental research different region of rabbit's ear (proximal, medial and distal) were punched as different geometrical shaped holes (circlc, quadrangle and triangle) with the same area (50 mm2) Ubyg a puncher which designed for this purpose. The regeneration of wounds was evaluated and the percentage of regeneration was calculated. After punching, each 3 days (36-40 days). Results: Results showed speed and percentage of regeneration in circular holes was significantly (P<0.05) more than quadrangular and triangular holes. In addition, regeneration speed of holes located in proximal regions of ear, was more than peripheral holes. Conclusion: Wound regeneration in rabbit's ear is related to the geometrical shape of holes. Speed and the percentage of regeneration in circular shapes is more than angular shapes.

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Abstract Background: Spinal cord slices culturing from adult mammals could be considered as a suitable in-vitro model for evaluating cellular viability, spinal cord injury and cell death mechanisms. In present study, determining of cell death in motor neurons of cultured spinal cord slices in adult mouse was done. Materials and Methods: In a experimental- laboratory study, thoracic regions of spinal cords from 4 Balb/c mice were cut into 400-µm slices using tissue chopper and incubated in a Co2 incubator at 37˚C for different periods of time. Freshly prepared slices (0h) and cultured slices were fixed and sectioned using cryostat. To study morphological and biochemical features of cell death, fluorescent staining, TUNEL method and agarose gel electrophoresis were used. Results: In freshly prepared slices of motor neurons showed no apoptotic changes. While, 6, 12 and 24h after culturing, this neurons displayed morphological features of apoptosis including cell shrinkage as well as nuclear and chromatin condensation. Also, 6 and 12h after culturing were TUNEL positive. In addition, extracted DNA from cultured slices for 24h were indicated the nucleosomal DNA fragmentation on agarose gel electrophoresis. Conclusion: Results were showed the occurrence of apoptosis in motor neurons of cultured adult mouse spinal cord slices.

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Background: Molybdenum is an essential trace element for both animals and plants. Molybdenum (Mo), which functions as a cofactor for a limited number of enzymes including xanthine dehyrogenase, aldehyde oxidase, and sulfite oxidase in mammals, is believed to be an essential trace element in animal nutrition. The aim of this study is to evaluate the hepatoprotective potential of sodium molybdate against carbon tetrachloride (CCl4) induced liver damage. Materials and Methods: In an experimental study, adult male rats received daily oral administrations of different doses of sodium molybdate (0.05, 0.1, and 0.2 g/kg bw) along with intrapertioneal CCl4 (50% CCl4 in olive oil, 1 ml/kg bw) twice a week for 28 consecutive days. Results: Histopathological examinations in CCl4-treated rats showed extensive liver injuries characterized by extensive hepatocellular degeneration and necrosis, fat degeneration, and inflammatory cell infiltration while histopathological changes induced by CCl4 were significantly attenuated by sodium molybdate treatment. Conclusion: The results of this study suggest that sodium molybdate could protect liver against the CCl4-induced oxidative damage in rats, and this hepatoprotective effect might be contributed to the protection of liver by preventing the toxic chemical reactions which generate oxidative stress, lipid peroxidation, and molecular changes which ultimately lead to liver tissue necrosis.

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Background: Arsenic as an environmental contaminant induces male infertility. Curcumin with potent antioxidant property is able to restrict oxidative stress. The aim of this study was to investigate the effect of curcumin on testis tissue and sperm count in adult mice treated with sodium arsenite.

Materials and Methods: In an experimental study, animals were divided into four groups: control, sodium arsenite (5 mg/kg), curcumin (100 mg/kg) and curcumin+sodium arsenite. Treatments were performed by intraperitoneal injection for five weeks. After treatment period, body weight was recorded. Left testis was dissected, weighed and used for the histopathological study of seminiferous tubules. Left cauda epididymis was also used to count sperm number.

Results: Mice treated with sodium arsenite showed a significant decrease in the sperm count, the diameter of seminiferous tubules and a significant increase in the lumen diameter of tubules compared to control group. In curcumin+sodium arsenite group, curcumin significantly reversed the adverse effects of sodium arsenite on testis and sperm count. Whereas, the treated mice showed no significant difference in body and testis weight as well as morphology and nuclear diameter of spermatogonia between four groups.

Conclusion: Curcumin is able to compensate the toxic effect of sodium arsenite on sperm count and testis in adult mouse.

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  Background: Alpha-tocopherol, as a strong antioxidant, plays an important role in testraining free radicals. The aim of this study was to investigate the effect of Alpha-tocopherol on cell proliferation and restraining apoptosis in rat bone marrow mesenchymal stem cells.

  Materials and Methods: In this research study, the rat bone marrow mesenchymal stem cells were extracted under sterile conditions using flashing-out method. At the end of the third passage, cells were divided into groups of control and Alpha-tocopherol with doses of 15 and 25 µM and were treated in the osteogenic media cell medium containing 10% fetal bovine serum, 10 mM β-glycerol phosphate, 10 nM dexamethasone and 50 µg/ml ascorbic 3-phosphate] for a period of 21 days. Then, cell proliferation, DNA damage, expression of Bcl-2 and Bax genes and the morphologic changes of the cells were investigated during the procedure of osteogenesis. Data were analyzed using one-way ANOVA and means difference was considered significant at p<0.05.

  Results: Cell proliferation, the size of nuclei diameter and expression of anti-apoptotic Bcl-2 gene showed a significant increase in mesenchymel stem cells treated with Alpha-tocopherol (p<0.05) in a dose dependent manner compared to the control cells. Also, cytoplasm extension was seen in the cells treated with Alpha-tocopherol, compared to the control group. Since Alpha-tocopherol causes a significant decrease in DNA damage and the expression of apoptotic Bax gene, compared to the control group, therefore it can suppress apoptosis in bone marrow mesenchymal stem cells, in a dose dependent manner .