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Aim: Previous studies demonstrated the neuroprotective effects of testosterone, but no previous study has examined the neuroprotective effects of testosterone on spinal cord ischemia/reperfusion injury. The purpose of this study was to evaluate whether testosterone could protect the spinal cord from ischemia/reperfusion injury., Methods: Rabbits were randomised into four groups of eight animals as follows: group 1 (control), group 2 (ischemia), group 3 (methylprednisolone) and group 4 (testosterone). In the control group only a laparotomy was performed. In all other groups, the spinal cord ischemia model was created by the occlusion of the aorta just caudal to the renal artery. Levels of malondialdehyde and catalase were analysed, as were the activities of caspase-3, myeloperoxidase, and xanthine oxidase. Histopathological and ultrastructural evaluations were performed. Neurological evaluation was performed with the Tarlov scoring system., Results: After ischemia-reperfusion injury, increases were found in caspase-3 activity, myeloperoxidase activity, malondialdehyde levels, and xanthine oxidase activity. In contrast, decreases in catalase levels were observed. After the administration of testosterone, decreases were observed in caspase-3 activity, myeloperoxidase activity, malondialdehyde levels, and xanthine oxidase activity, whereas catalase levels increased. Furthermore, testosterone treatment showed improved results concerning histopathological scores, ultrastructural score and Tarlov scores., Conclusions: Our results revealed for the first time that testosterone exhibits meaningful neuroprotective activity following ischemia-reperfusion injury of the spinal cord., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Background: Darbepoetin-alpha (DA) is a novel erythropoiesis-stimulating agent developed for treating anemia. In animal models, recombinant human erythropoietin has been reported to be beneficial for neuroprotection. In this study, we determined whether DA would protect the spinal cord against ischemia-reperfusion injury in a rabbit model., Methods: Forty rabbits were randomized into five groups of eight animals each: group 1 (sham), group 2 (ischemia), group 3 (vehicle), group 4 (30 mg/kg methylprednisolone), group 5 (30 μg/kg DA). Only laparotomy was performed in the sham group. In all the other groups, the spinal cord ischemia model was created by a 20-min occlusion of the aorta just caudal to renal artery with an aneurysm clip. The drugs were administered immediately after the clamp was removed. The animals were killed 24 h later. Spinal cord segments between L2 and L5 were harvested for analysis. Neurological evaluation was performed with the Tarlov scoring system just before the animals were killed. Level of tissue malondialdehyde was analyzed as a marker of lipid peroxidation and tissue caspase-3 activity as a marker of apoptosis. Also, histopathological evaluation of the tissues was performed., Results: Both malondialdehyde and caspase-3 levels were significantly decreased by DA administration. Histopathological evaluation of the tissues also demonstrated decrease in neuronal degeneration and infiltration parameters after DA administration. In the DA group, neurological outcome scores were statistically significantly better compared with the ischemia and the vehicle groups., Conclusions: Although further studies considering different dose regimens and time intervals are required, DA was shown to be at least as effective as methylprednisolone in spinal cord ischemia/reperfusion model.

Although the precise mechanism by which ischemia/reperfusion injury occurs in the spinal cord remains unclear, it is evident that free oxygen radicals and apoptosis play major roles in the destruction of membrane lipids, damage to DNA and cell death. The apoptotic process involves activation of the caspase-3 cascade. Although it is widely used as a protective agent against cell injury, it is unknown whether mesna (2-mercaptoethane sulfonate) ameliorates neuronal ischemic injury. The aim of this study was to determine the effect of mesna on caspase-3 activity in a rabbit model. Adult rabbits underwent spinal cord ischemic injury via occlusion of the abdominal aorta for 20 min. Twenty-four hours after ischemia, spinal cord samples were obtained and tissue caspase-3 activity was measured. Rabbits that had been given a single dose of 150 mg/kg mesna had decreased caspase-3 activity in the spinal cord following ischemia/reperfusion injury, indicating a protective effect. However, caspase-3 activity was lower in rabbits given methylprednisolone than in those given mesna, indicating that methylprednisolone has the stronger protective effect of the two agents., ((c) 2009 Elsevier Ltd. All rights reserved.)