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The effect of ionizing irradiation on testes and the protective effects of melatonin were investigated by immunohistochemical and electron microscopic methods. Eighty-two adult male Wistar rats were divided into 10 groups. The rats in the irradiated groups were exposed to a sublethal irradiation dose of 8 Gy, either to the total body or abdominopelvic region using a 60 Co source at a focus of 80 cm away from the skin in the morning or evening together with vehicle (20% ethanol) or melatonin administered 24 h before (10 mg/kg), immediately before (20 mg/kg) and 24 h after irradiation (10 mg/kg), all ip. Caspace-3 immunoreactivity was increased in the irradiated group compared to control (P < 0.05). Melatonin-treated groups showed less apoptosis as indicated by a considerable decrease in caspace-3 immunoreactivity (P < 0.05). Electron microscopic examination showed that all spermatogenic cells, especially primary spermatocytes, displayed prominent degeneration in the groups submitted to total body and abdominopelvic irradiation. However, melatonin administration considerably inhibited these degenerative changes, especially in rats who received abdominopelvic irradiation. Total body and abdominopelvic irradiation induced identical apoptosis and testicular damage. Chronobiological assessment revealed that biologic rhythm does not alter the inductive effect of irradiation. These data indicate that melatonin protects against total body and abdominopelvic irradiation. Melatonin was more effective in the evening abdominopelvic irradiation and melatonin-treated group than in the total body irradiation and melatonintreated group.

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The process of wound healing begins immediately following surface lesions or just after exposure to radiation, chemical agents or extreme temperatures. Taurine (2-aminoethane sulfonic acid), an amino acid containing sulfur, is found in almost all tissues in mammals, playing various important physio-logical roles in each organ. Taurine exhibits an antioxidant effect and is also known to have effects on cell proliferation, inflammation and collagenogenesis. Many antioxidants have been used to eliminate the negative effects of oxygen free radicals on wound healing. The objective of the present study was to examine the wound healing effect in mice of taurine-chitosan gel, which releases taurine slowly over a long time period. Fifty mM of taurine in 1.5% chitosan polymer (TAU-GEL) and 1.5% chitosan polymer (CHI-GEL) were applied to full thickness skin wounds of mice once a day for seven days. After seven days of treatment, lipid peroxide formation-malondialdehyde (MDA) and hydroxyproline (HPX) levels and the tensile strength of wound tissues were measured. All results were compared with those of the untreated control group (CONT). The structural alterations in the skin layers were also histologically investigated. It was found that locally administered TAU-GEL form significantly increased wound tensile strength by decreasing the MDA and increasing HPX levels. These results were supported by histological findings. All observations suggest that taurine gel may be effective in wound healing.

Cyclooxygenase (COX), which have the isoforms of COX-1 and COX-2, is the key enzyme of prostaglandins biosynthesis. Especially, COX-2 is induced in inflammatory disease such as Diabetes Mellitus (DM). Resveratrol (RSV), a natural antioxidant, has a beneficial role in prevention of inflammatory disease. We investigated the changes of COX-1 and COX-2 mRNA expression and protein level in diabetic rat kidney after RSV treatment. Three months-old, 44 Wistar albino male rats, which were divided into six groups such as control group, sodium citrate buffer (sham control) group, diabetic group (DM), Dimethyl Sulfoxide induced control group, RSV treated sham control group (RSV) and RSV treated diabetic group (DM + RSV) were used for the study. Experimental diabetes was induced by intraperitoneal injection of 55 mg/kg Streptozotocin. After the induction of chronic diabetes 10 mg/kg per day RSV was administered intraperitoneally for 4 weeks. In this study. RSV has no significant effect on COX-1 mRNA expression in diabetic rat kidney (P > 0.05). Immunohistochemical study showed that COX-1 expression was slightly inhibited in RSV group and was not significantly supressed in DM + RSV group. When comparing control and treated groups, there were no significant differences in COX-2 mRNA or protein levels (P > 0.05). In conclusion, our results indicate that resveratrol do not significantly affect COX gene and protein expression. Therefore, different therapy strategies such as combination with other antidiabetic drugs may tried in STZ induced animal model for reducing diabetic symptoms and altering COX-1 and COX-2 mRNA or protein levels.