PURPOSE:To investigate whether N-acetylcysteine, a free radicals scavenger has a protective effect against lung injury as a remote organ after skeletal muscle ischemia-reperfusion. METHODS: Twenty Wistar male rats were divided randomly into two experimental groups: group ischemia-reperfusion (group I) and group ischemia-reperfusion + N-acetylcysteine (group II). All animals were undergone two hours of ischemia by occlusion femoral artery and 24h of reperfusion. Before clamped the femoral artery, 250 IU heparin was administered via the jugular vein to prevent clotting. Rats that were treated with N-acetylcysteine given IV at a dose of 150 mgkg-1 , immediately before reperfusion. After 24h of reperfusion, animals were euthanized and left lung harvested for histopathological analysis under light microscopy. RESULTS: In the group I, tissues showed histological changes with intra-alveolar edema, intra-alveolar hemorrhage and neutrophilic infiltration. Histopathologically, there was a significant difference (P = 0.005) between two groups. CONCLUSION: Administration of N-acetylcysteine treatment significantly decreased lung injury induced by skeletal muscle ischemia reperfusion according to histological findings. Key words: Acetylcysteine. Muscle, Skeletal. Lung. Ischemia. Reperfusion. Reperfusion Injury. Histology. Rats. RESUMO OBJETIVO:Investigar se N-acetilcisteína, neutralizador de radicais livres, tem efeito protetor contra dano pulmonar como um órgão remoto após isquemia-reperfusão de músculo esquelético. MÉTODOS: Vinte ratos machos Wistar, foram aleatóriamente distribuídos em dois grupos: grupo isquemia-reperfusão (grupo I) e grupo isquemia-reperfusão +N-acetilcisteína (grupo II). Todos os animais foram submetidos a duas horas de ischemia pela oclusão artéria femoral e 24 horas de reperfusão. Antes de ocluir a artéria femoral, foi administrado 250 IU de heparina pela veia jugular para prevenir coagulação. A N-acetilcisteína foi administrada por via intravenosa, na uma dose de 150 mgkg -1 , imediatamente antes de reperfusão. Após 24 horas de reperfusão, os animais foram eutanasiados e o pulmão esquerdo foi removido para análise histológica em microscopia óptica. RESULTADOS: No grupo I, os tecidos mostraram alterações histológicas com edema e hemorragia intra-alveolar e infiltração neutrofílica. Houve diferença histopatológica significante (P = 0.005) entre os dois grupos. CONCLUSÃO: O tratamento com a N-acetilcisteína diminuiu significantemente o dano pulmonar induzido por isquemia-reperfusão de músculo esquelético Descritores: Acetilcisteína. Músculo Esquelético. Pulmão. Isquemia. Reperfusão. Traumatismo por Reperfusão. Histologia. Ratos. Effect of N-acetylcysteine on lung injury induced by skeletal muscle ischemia-reperfusion.Histopathlogical study in rat model

OBJECTIVE: To determine whether tramadol has a protective effect against lung injury induced by skeletal muscle ischemia-reperfusion. METHODS: Twenty Wistar male rats were allocated to one of two groups: ischemia-reperfusion (IR) and ischemia-reperfusion + tramadol (IR+T). The animals were anesthetized with intramuscular injections of ketamine and xylazine (50 mg/kg and 10 mg/kg, respectively). All of the animals underwent 2-h ischemia by occlusion of the femoral artery and 24-h reperfusion. Prior to the occlusion of the femoral artery, 250 IU heparin were administered via the jugular vein in order to prevent clotting. The rats in the IR+T group were treated with tramadol (20 mg/kg i.v.) immediately before reperfusion. After the reperfusion period, the animals were euthanized with pentobarbital (300 mg/kg i.p.), the lungs were carefully removed, and specimens were properly prepared for histopathological and biochemical studies. RESULTS: Myeloperoxidase activity and nitric oxide levels were significantly higher in the IR group than in the IR+T group (p = 0.001 for both). Histological abnormalities, such as intra-alveolar edema, intra-alveolar hemorrhage, and neutrophil infiltration, were significantly more common in the IR group than in the IR+T group. CONCLUSIONS: On the basis of our histological and biochemical findings, we conclude that tramadol prevents lung tissue injury after skeletal muscle ischemia-reperfusion.

It is known that ischemia reperfusion causes remote organ injury as well as local injury. The aim of this study was to investigate whether N-acetylcysteine has a protective effect against testicular injury after skeletal muscle ischemia reperfusion. Twenty male Wistar rats were allocated to two groups: ischemia reperfusion (control group) and ischemia reperfusion + N-acetylcysteine (treatment group). All animals underwent 2 h of ischemia by occlusion of the femoral artery and 24 h of reperfusion. Rats in treatment group received N-acetylcysteine (150 mg/kg IV) before the reperfusion period. After the reperfusion period, testes were removed for histopathological and biochemical studies. The blood samples were collected for evaluation of serum malondialdehyde (MDA) and nitric oxide (NO) production levels. The MDA levels in testes homogenates were found to be significantly decreased in treatment group (p < 0.05). Treatment of N-acetylcysteine significantly decreased serum MDA and NO levels compared to the control group (p < 0.05). In the control group, tissues showed histological changes. Histopathologically, there was a significant difference (p < 0.05) between two groups. According to histological and biochemical findings, we conclude that N-acetylcysteine has preventive effects in the testicular injury after skeletal muscle ischemia reperfusion.

PURPOSE:To investigate if the methanolic extract of the Otostegia persica can accelerating healing process of burn wound because of its anti-inflammatory and antioxidant effects. METHODS:Forty eight male Wistar rats were randomized into three study groups of 16 rats each. Burn wounds were created on dorsal part of shaved rats using a metal rod. In group I the burn wound was left without any treatment. Group was treated with topical silver sulfadiazine pomade. In group III, ointment containing the OP extract was administered. Skin biopsies were harvested from burn area on the 3rd, 5th, 14th and 21st days after burn and examined histologically. RESULTS:Re-epithelialization in the control group and in group II was lower than in group III. Re-epithelialization in groups II and III was significantly different from that in the control group. On the 5th day of the experiment, we assessed lower inflammation in the burn area compared to control group. This means that the inflammation was suppressed by methanolic extract of OP. From day 5 to 14; the fibroblast proliferation peaked and was associated with increased collagen accumulation. It was obvious that angiogenesis improved more in the groups II and III, which facilitated re-epithelialisation. CONCLUSION:Methanolic extract of Otostegia persica exhibited significant healing activity when topically applied on rats. OP is an effective treatment for saving the burn site.

PURPOSE: Articular Cartilage has limited potential for self-repair and tissue engineering approaches attempt to repair articular cartilage by scaffolds. We hypothesized that the combined hydroxyapatite and zirconia stabilized yttria would enhance the quality of cartilage healing. METHODS:In ten New Zealand white rabbits bilateral full-thickness osteochondral defect, 4 mm in diameter and 3 mm depth, was created on the articular cartilage of the patellar groove of the distal femur. In group I the scaffold was implanted into the right stifle and the same defect was created in the left stifle without any transplant (group II). Specimens were harvested at 12 weeks after implantation, examined histologically for morphologic features, and stained immunohistochemically for type-II collagen. RESULTS:In group I the defect was filled with a white translucent cartilage tissue In contrast, the defects in the group II remained almost empty. In the group I, the defects were mostly filled with hyaline-like cartilage evidenced but defects in group II were filled with fibrous tissue with surface irregularities. Positive immunohistochemical staining of type-II collagen was observed in group I and it was absent in the control group. CONCLUSION:The hydroxyapatite/yttria stabilized zirconia scaffold would be an effective scaffold for cartilage tissue engineering.

PURPOSE: To investigate whether N-acetylcysteine has a protective effect against renal injury as a remote organ after skeletal muscle ischemia-reperfusion in rats. METHODS: Twenty Wistar male rats were divided randomly into two experimental groups: group ischemia-reperfusion (group I) and group ischemia-reperfusion + N-acetylcysteine (group II). After ketamine and xylazine anesthesia, femoral artery was exposed. All animals were undergone 2h of ischemia by occlusion femoral artery and 24h of reperfusion. Rats that were treated with N-acetylcysteine given IV at a dose of 150 mg/kg-¹, immediately before reperfusion. After 24h of reperfusion, the blood samples were collected and submitted for evaluation of plasmatic urea, creatinine values and then rats were euthanized and left kidney harvested for histopathological analysis under light microscopy. RESULTS: The urea (35±7.84 mg.dL-1), creatinine (1.46±0.47 mg.dL-1) values were significantly lower in group II (P=0.000). Renal histopathologic study in group I showed extensive distal and proximal tubular cells necrosis and sloughing of epithelial cells into the tubular lumen, cast formation in tubule and glomerul, glomerul fibrosis and hemorrhage. Histopathologically, there was a significant difference (p=0.037) between two groups. CONCLUSION: The N-acetylcysteine was able to decrease renal injury induced by skeletal muscle ischemia reperfusion in rats.

Acceleration of bone healing has always been a major challenge in orthopedic surgery, the aim of this study was an evaluation of the biological effects of zirconia-stabilized yttria on bone healing, using an in vivo model. Nano-hydroxyapatite powder with zirconia-stabilized yttria were inserted in rabbit tibia and then histologically analyzed and compared with non-treated controls so thirty six. New Zealand white male rabbits randomly divided into two groups of 18 rabbits each. A cortical hole of 4 mm diameter and 8 mm depth in each tibia was drilled. In group I, the defect was left empty, whereas in group II, the bone defect was packed with nano-hydroxyapatite/5% zirconia stabilized with yttria. Histological evaluations were performed at two, four and six weeks after the implantation. Microscopic changes on two groups along with the time course were scored and statistical analysis showed that the average scores in group II were significantly higher than the other groups (p < 0.05). Histological analysis was shown to be significantly improved by the nano-hydroxyapatite/5% zirconia stabilized with yttria compared with the control group, suggesting that this biomaterial promote the healing of cortical bone, presumably by acting as an osteoconductive.

PURPOSE:To investigate if low level laser therapy (LLLT) can decrease spinal cord injuries after temporary induced spinal cord ischemia-reperfusion in rats because of its anti-inflammatory effects. METHODS:Forty eight rats were randomized into two study groups of 24 rats each. In group I, ischemic-reperfusion (I-R) injury was induced without any treatment. Group II, was irradiated four times about 20 minutes for the following three days. The lesion site directly was irradiated transcutaneously to the spinal direction with 810 nm diode laser with output power of 150 mW. Functional recovery, immunohistochemical and histopathological changes were assessed. RESULTS:The average functional recovery scores of group II were significantly higher than that the score of group I (2.86 ± 0.68, vs 1.38 ± 0.09; p<0.05). Histopathologic evaluations in group II were showed a mild changes in compare with group I, that suggested this group survived from I-R consequences. Moreover, as seen from TUNEL results, LLLT also protected neurons from I-R-induced apoptosis in rats.CONCLUSION: Low level laser therapy was be able to minimize the damage to the rat spinal cord of reperfusion-induced injury.