| Background and objectiveIntracerebral hemorrhage (ICH) is an acute cerebrovascular disease of high incidence, morbidity, high mortality, which does serious harm to people’s health. In recent years, the incidence rate of ICH has been increasing, but it still lacks a particularly effective treatment. After ICH, the primary injury caused by the hematoma itself and the secondary injury caused by the cerebral ischemia which resulted from the hemorrhage, were the main pathologic changes after the bleeding.Studies suggest that the damage after intracerebral hemorrhage is associated with the inflammation and apoptosis. Caspase-3is the key enzyme and the final effector of apoptosis. In the ischemic area of brain tissue damage, the delayed death of brain cells is related with caspase-3-dependent signal transduction pathway, caspase-3can be stimulated by various means, resulting in the cascade reaction amplification effect, ultimately leading to DNA breaks, which leads to cell apoptosis, so it is also known as "killer protease". As a neuroprotective agent, magnesium sulfate has been used in clinical. Animal and clinical researches at home and abroad have already proved that magnesium sulfate has the function of nerve protection for brain ischemia injury. Its mechanism is not entirely clear.It is considered that the magnesium ion is a calcium antagonist, which has the effect of inhibiting the overload of intracytoplasmic Ca2+, the antagonist of excitatory amino acid toxic effects and adjustment of cerebral blood flow, restoring the ischemic area blood supply, reducing free radical generation.In this study, magnesium sulfate was intervened on the rat model of intracerebral hemorrhage, the expression of caspase-3and apoptotic cells were observed by immunohistochemical methods to explore its possible mechanism in intracerebral hemorrhage treatment, to open up new ideas for each phase of intracerebral hemorrhage treatment and provide new theoretical basis.Materials and Methods108adult male Sprague Dawley (SD) rats, based on the number table, were randomly divided into sham operation group, model group and the magnesium sulfate intervention group. Each group has36members. By the application of stereotactic techniques, autologous blood was injected into the rat caudate nucleus to prepare intracerebral hemorrhage model, after the success of modeling, the intervention group was injected intraperitoneal with25%magnesium sulfate400mg/kg. Each rat of the sham operation group and model group rats was injected the same amount of saline1/d, After the surgery, each group was randomly divided into six time points, which were Id,3d,7d,14d,21d,28d. And at each time point six rats were taken out. until the corresponding point of time. The neural function score of a model rat is evaluated by Zea-longa score. Apoptotic cells and caspase-3were immunohistochemically stained in the SP method. Each slice was determined by the optical density of four fields (×200) and took the average value as the measured value in Biosens the Digital Imaging System v1.6analysis system.The data were statistically analyzed by the SPSS17.0statistical software. All data were said by mean±standard deviation, the mean comparison between groups was achieved by using single factor analysis of variance. And the test standard was based on alpha=0.05.Results1Tunel Dying:Model group and the intervention group had the same trend in the expression of apoptotic cells. After the intracerebral hemorrhage, in the intrahematoma and perihematomal hemorrhage a number of TUNEL-positive cells were seen on the first day. And the number increased significantly on the7d, reached a peak, and then gradually decreased. After the intervention of magnesium sulfate, the number of TUNEL-positive cells decreased significantly, at each time point, than in the model group (P<0.05).2Caspase-3Immunohistochemical Staining:At each corresponding time point in the sham operation group, only a small amount of Caspase-3was expressed. In the model group, caspase-3positive cells expression began to increase form the first day, and reached a peak on the7d, then decreased gradually in the intrahematoma and perihematomal brain tissue and gradually returned to normal levels until the28d. In the magnesium sulfate intervention group, compared with the model group, at each time point the expression of caspase-3positive cells in the hematoma and perihematomal brain tissue reduced significantly (P<0.05).Conclusions1. The expression of Caspase-3and apoptotic cells is high after intracerebral hemorrhage,2. The generation of apoptotic cells may be associated with the increased expression of caspase-3.3. Magnesium sulfate reduces the generation of apoptotic cells by inhibiting Caspase-3expression, which suggests that magnesium sulfate has a certain effect in the treatment of intracerebral hemorrhage in clinical applications. |
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