【摘要】 探讨黄芪汤对受¹²C⁶⁺离子束照射后大鼠大脑中Bax、Bcl-2与Caspase-3表达的影响。无特定病原体（Specific pathogen free,SPF）级Wistar大鼠50只随机分为正常对照组,单纯辐照模型组,黄芪汤高、中、低剂量组,每组各10只。常规饲养7 d后,黄芪汤高、中、低剂量组用黄芪汤（剂量分别为18 g/（kg·d）、9 g/（kg·d）、4.5 g/（kg·d））灌胃2周,正常对照组和单纯辐照模型组用等量生理盐水灌胃。从第7天起除正常对照组外,其余各组大鼠脑组织给予4 Gy¹²C⁶⁺离子束单次照射,辐照后第7天称量各组大鼠的体重,10%水合氯醛（3 m L/kg）麻醉各组大鼠后股动脉采血处死大鼠。计算各组大鼠的脑系数,HE染色法及TUNEL染色法观察脑组织病理学形态改变,并计算神经细胞凋亡率,实时荧光定量PCR法测定各组大鼠脑组织Bcl-2、Bax和Caspase-3的基因表达,Western-Blot法检测各组大鼠脑组织Bcl-2、Bax和Caspase-3的蛋白表达。单纯辐射模型组体重和脑系数均降低,脑组织存在大量凋亡细胞,脑组织Bcl-2的基因表达和蛋白表达均降低,Bax和Caspase-3的基因表达和蛋白表达均升高（p<0.01）。黄芪汤中、高剂量组脑系数升高,黄芪汤高剂量组体重、脑组织Bcl-2的基因表达和蛋白表达均升高（p<0.05或p<0.01）;而黄芪汤中、高剂量组脑组织细胞凋亡率明显降低,Caspase-3的基因表达和蛋白表达均显著降低,高剂量组Bax的基因表达和蛋白表达均显著降低（p<0.01）。病理组织学检查发现单纯辐射模型组大鼠脑组织稀疏,细胞数量明显减少且间隙增大;黄芪汤高剂量组脑组织稀疏,脑细胞数量减少及间隙增宽等情况较单纯辐射组明显好转,但未完全恢复正常。黄芪汤对¹²C⁶⁺离子束辐射所致的Wistar大鼠脑损伤具有较好的保护作用,其抗辐射作用可能主要是通过抑制大鼠脑组织Bax、Caspase-3的表达和促进其脑组织Bcl-2的表达来实现的。更多还原

【Abstract】 To explore the effect of Huangqi decoction on Bax, Bcl-2, and Caspase-3 expressions in rat brain tissues irradiated by¹²C⁶⁺ion beam, 50 Wistar rats were randomly divided into five groups—normal control group,radiation alone model group, and high-, medium-, and low-dose Huangqi decoction groups. After 7 days of routine feeding, rats in the high-, medium-, and low-dose Huangqi decoction groups were administered Huangqi decoction[18 g/（kg·d）, 9 g/（kg·d）, 4.5 g/（kg·d）] by gavage for 2 weeks. The normal control group and radiation alone group were administered the same volume saline by gavage. From the 7 th day, the brain of the rats of the radiation alone model group and high-, medium-, and low-dose Huangqi decoction groups were radiated once by 4 Gy¹²C⁶⁺ion. The brain of rats in the normal control group were not radiated. The rats were anesthetized with 10% chloral hydrate（3 mL/kg）, and blood was collected from the femoral artery 7 days after irradiation. To calculate the brain coefficient with weighing, pathomorphism changes in the brain tissues were observed using hematoxylin and eosin and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling staining, and the apoptosis percentage of nerve cells was calculated. Bcl-2, Bax, and Caspase-3 gene expressions in the brain tissues were assessed using reverse-transcriptase polymerase chain reaction, and Bcl-2, Bax, and Caspase-3 protein expressions in the brain tissues were analyzed using western blotting. The body weight and brain coefficient significantly decreased; the apoptosis percentage of nerve cells had evidently increased; the gene and protein expressions of Bcl-2 in the brain tissues significantly decreased; the gene and protein expressions of Bax and Caspase-3 in the brain tissues significantly increased in the radiation alone model group（p<0.01）. The brain coefficient increased in the medium-and high-dose Huangqi decoction groups; the body weight and the gene and protein expressions of Bcl-2 increased significantly in the high-dose group（p<0.05 and p<0.01, respectively）. The apoptosis percentage of nerve cells was evidently declined in the medium-and high-dose Huangqi decoction groups; the gene and protein expressions of Caspase-3 decreased significantly in the medium-and high-dose Huangqi decoction groups; the gene and protein expressions of Bax decreased significantly in the high-dose Huangqi decoction group（p<0.01）. The result of histopathologic examination displayed sparse cerebral tissues in the radiation alone model group, with the decreased amount of cells and enlarged interspace, while sparse cerebral tissues, the decreased amount of cells and enlarged interspace were obviously improved, but it did not return to normal. The protective effect of Huangqi decoction against brain injury induced by¹²C⁶⁺ion beam radiation is achieved mainly by controlling the upregulation of Bax and Caspase-3 expressions and the down-regulation of Bcl-2 expression.更多还原