玉郎伞多糖对放射性腮腺损伤模型大鼠的保护作用及其机制研究

目的:探究玉郎伞多糖对放射性腮腺损伤模型大鼠的保护作用及其机制。方法:将75只雄性SD大鼠随机分为5组,每组15只:正常对照组、模型对照组、玉郎伞多糖150、300、600 mg/kg组。于照射前开始1周各组分别灌胃给予相应药物或生理盐水,连续80日。造模大鼠麻醉后用15 Gy,DTγ射线照射大鼠双侧腮腺组织,正常对照组仅麻醉不予照射。照射后观察大鼠体重,饮食进水等一般情况的改变,分别于照射后第10 d、第40 d、第70 d腹主动脉取血处死大鼠后检测大鼠血清淀粉酶(AMS)及活性氧族(ROS)的含量,肉眼观察大鼠腮腺大体标本后将腮腺完整取下,称取大鼠腮腺质量,取部分腮腺进行HE染色、TUNEL染色及免疫组织化学法检测B淋巴细胞瘤-2基因(Bcl-2)、Bcl2-Associated X的蛋白质(Bax)、增殖细胞核抗原(PCNA)及肿瘤坏死因子(TNF-α)的表达。结果:与正常组比较,模型组血清AMS含量,先明显升高后显著降低,血清ROS含量明显升高,细胞凋亡率明显升高,腮腺组织中Bcl-2表达明显下调,Bax、PCNA、TNF-α蛋白表达明显上调。玉郎伞多糖可改善照射后大鼠腮腺的损伤,减少腮腺细胞的凋亡率及下调Bax、PCNA、TNF-α蛋白的阳性表达率,上调Bcl-2蛋白的阳性表达率,明显降低血清中ROS含量,先降低后增高血清AMS含量。结论:玉郎伞多糖对放射性腮腺损伤模型大鼠有保护作用,其机制可能与抑制腮腺细胞凋亡及清除大鼠照射后ROS活性有关。

Effects of helium on titanium films and the helium diffusion

Using direct current-magnetron sputtering,Helium-trapped Ti films with a He/Ar mixture was studied.The relative helium content,helium depth profiles for the Ti films and crystallization capacity were analyzed by Enhanced Proton Backscattering Spectrometry(EPBS)and X-ray diffraction(XRD).It was found that helium diffusion enhanced as more helium trapping into Ti films,and the He holding ratios were 95.9%,94.9%,93.9%,82.8% when the Ti films with the He/Ti of concentrations of 9.7 at.%,19.5 at.%,19.7 at.%,48.3 at.% were measured again 4 months later,respectively.The diffraction peaks be-came weak and wider,the peak of(002)plane was shifted to smaller diffraction angles and the relevant interplanar spacing d(hkl)increased gradually as more helium trapping into Ti films.The main peak was made trending to the(101)plane by both higher deposition temperature and more helium trapping.