动物造模,脑外伤 中国实验动物信息网 2024-01-16 604

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

　　Methods The Feeney method was used to prepare the rat model of traumatic brain injury. The SD rats that were successfully established were randomly divided into model group, DAHP group, NOS activator group (tetrahydrobiopterin (BH4) group), and DAHP+BH4 group. There were 12 rats in each group, and another 12 rats were selected as the sham-operated group, only the bone window was opened without the blower. 2 h after modeling, the DAHP group was injected with 0.5 g/kg of DAHP, the BH4 group was injected with 0.3 mg/kg of BH4, and the DAHP+BH4 group was injected with 0.5 g/kg of DAHP and DAHP. 0.3 mg/kg of BH4, the sham-operated group and the model group were injected with the same volume of normal saline, the injection volume was 10 mL/kg, once a day, for 1 week. After the last treatment, positioning navigation and space exploration experiments were used to evaluate the behavior of the rats; hematoxylin-eosin (HE) staining was used to observe the morphological changes of rat brain tissue; Tunel staining was used to observe the apoptosis of brain tissue; Griess method was used to detect the monoxide in brain tissue. Nitrogen (NO) levels; Western blotting to detect neural nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), nuclear factor-κB (NF-κB), tumor necrosis factor in rat brain tissue -α (TNF-α), Cyclooxygenase-2 (COX-2), Caspase-3 (Caspase-3), B-lymphoma-2 gene (Bcl-2) protein express the situation.

　　Results The nerve cells in the brain tissue of the sham operation group had normal morphology and uniform coloration of the nucleus; the nerve cells in the model group were swollen, deformed, pyknotic, accompanied by inflammatory cell infiltration; compared with the model group, the morphology of nerve cells in the DAHP group was relieved to a certain extent. , the degree of inflammatory infiltration was relieved, the number of necrotic nerve cells increased in BH4 group, and the degree of injury was aggravated, and 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, Bcl-2 protein in brain tissue, apoptosis rate, nNOS, iNOS protein expression, NO level, NF-κB, TNF-α in brain tissue were decreased. The protein expressions of α, COX-2 and Caspase-3 were increased (P<0.05). Compared with the model group, the escape latency of the rats in the DAHP group was shortened, the proportion of space exploration time, Bcl-2 protein in brain tissue, apoptosis rate, nNOS, iNOS protein expression, NO level, NF-κB, TNF-α in brain tissue were increased. The protein expressions of α, COX-2 and Caspase-3 were decreased (P<0.05). Compared with the model group, the escape latency of the rats in the BH4 group was prolonged, the proportion of space exploration time, the Bcl-2 protein in the brain tissue was decreased, the apoptosis rate of the brain tissue, nNOS, iNOS protein expression, NO level, NF-κB, TNF-α , COX-2, Caspase-3 protein expression increased (P<0.05). The escape latency, brain tissue apoptosis rate, nNOS, iNOS protein expression, NO level, NF-κB, TNF-α, COX-2, Caspase-3 protein expression in the DAHP+BH4 group were lower than those in the BH4 group, and the spatial exploration time was shorter than that in the BH4 group. The ratio of Bcl-2 protein expression in brain tissue was higher than that in BH4 group (P<0.05).

　　Conclusion DAHP can alleviate the neurological damage in rats with traumatic brain injury and reduce the apoptosis of nerve cells in brain tissue, and its mechanism may be related to the inhibition of iNOS signaling pathway.