动物造模,脑外伤 z-bio 2022-12-12 345

　　Objective To explore the neuroprotective effect of 2,4-diamino-6-hydroxypyrimidine (DAHP) on brain injury in rats and its possible mechanism.

　　Methods The rat model of brain injury was prepared by Feeney method. The SD rats that were successfully modeled were randomly divided into model group, DAHP group, NOS activator group (BH4 group), DAHP+BH4 group, with 12 rats in each group. Another 12 rats were selected as sham operation group, which only opened the bone window and did not take percussion device. Two hours after modeling, 0.5 g/kg of DAHP was injected into the tail vein of DAHP group, 0.3 mg/kg of BH4 was injected into the tail vein of BH4 group, 0.5 g/kg of DAHP and 0.3 mg/kg of BH4 were injected into the tail vein of DAHP+BH4 group, and the sham operation group and model group were injected with the same amount of normal saline with the injection volume of 10 mL/kg. The drug was administered once a day for one week. After the last treatment, the behavior of rats was evaluated by positioning navigation and space exploration experiments; Hematoxylin eosin (HE) staining was used to observe the morphological changes of brain tissue in rats; Tunel staining was used to observe the apoptosis of brain cells; The level of nitric oxide (NO) in brain tissue was measured by Griess method; Detection of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS) and nuclear factor in rat brain tissue by Western blot- κ B(NF- κ B) Tumor necrosis factor- α (TNF- α)、 Expression of COX-2, Caspase-3 and Bcl-2 proteins.

　　Results In the sham operation group, the morphology of nerve cells in brain tissue was normal, and the nucleus staining was uniform; In the model group, the nerve cells were swollen, deformed, pyknotic, accompanied by inflammatory cell infiltration; Compared with the model group, the histological morphology of nerve cells in DAHP group was alleviated to some extent, and the degree of inflammatory infiltration was reduced. The number of necrotic nerve cells in BH4 group increased, and the degree of injury was aggravated. The morphological changes of cells in DAHP+BH4 group were not significant. Compared with the sham operation group, the escape latency of rats in the model group was prolonged, the proportion of space exploration time, the Bcl-2 protein in brain tissue was reduced, the apoptosis rate of brain cells, the expression of nNOS, iNOS protein, the level of NO, NF- κ B、 TNF- α、 The expression of COX-2 and Caspase-3 protein increased (P<0.05). Compared with the model group, the escape latency of rats in DAHP group was shortened, the proportion of space exploration time, the Bcl-2 protein in brain tissue was increased, and the apoptosis rate, nNOS, iNOS protein expression, NO level, NF in brain tissue were also increased- κ B、TNF- α、 The expression of COX-2 and Caspase-3 protein decreased (P<0.05). Compared with the model group, the escape latency of rats in BH4 group was prolonged, the proportion of space exploration time, the Bcl-2 protein in brain tissue was reduced, the apoptosis rate of brain cells, the expression of nNOS, iNOS protein, the level of NO, NF- κ B、TNF- α、 The expression of COX-2 and Caspase-3 protein increased (P<0.05). Escape latency, apoptosis rate of brain tissue, nNOS, iNOS protein expression, NO level, NF in DAHP+BH4 group- κ B、 TNF- α、 The expression of COX-2 and Caspase-3 protein was lower than that of BH4 group, while the proportion of space exploration time and the expression of Bcl-2 protein in brain tissue were higher than that of BH4 group (P<0.05).

　　Conclusion DAHP can alleviate the damage of nerve function and the apoptosis of nerve cells in brain tissue of rats with brain trauma, and its mechanism may be related to the inhibition of iNOS signal pathway.