Valsartan延缓血管内皮细胞衰老及p16INK4a表达变化的研究

目的 探讨Valsartan对血管内皮细胞衰老与p16INK4a表达变化的影响,为寻求廷缓内皮细胞衰老途径提供理论和实验依据.方法 体外培养人脐静脉内皮细胞,子血管紧张素Ⅱ及Valsartan干预,实验分为空白对照组、血管紧张素Ⅱ诱导组及Valsartan组,采用β-半乳糖苷酶(β-gal)染色鉴定细胞衰老;流式细胞术分析细胞周期变化;免疫细胞化学染色法、Western blot分析各组细胞p16INK4a蛋白的表达.结果 与对照组比较,血管紧张素Ⅱ诱导组β-半乳糖苷酶阳性染色率显著增多81.24％±6.46％,细胞周期停滞于G0-G1(88.36％±6.45％),p16INK4a 蛋白表达水平上调(P＜0.05);予以Valsartan干预后,β-半乳糖苷酶阳性细胞染色率减少,G0-G1细胞减少,p16INK4a蛋白表达水平下调(P＜0.05).结论 血管内皮细胞衰老分子机制可能通过下调p16INK4a的表达,使细胞周期停滞于G1期有关,Valsartan对血管内皮细胞衰老有一定保护作用,可能通过调控p16INK4a的表达发挥其延缓3血管内皮细胞衰老的作用.     

人参皂甙Rg3对血管平滑肌细胞衰老的影响及机制

目的探讨人参皂甙Rg3对D-半乳糖诱导的血管平滑肌细胞(vascular smooth muscle cells,VSMC)衰老的影响及机制。方法取SD大鼠胸主动脉中层,分离并原代培养VSMC,选取3~6代VSMC,通过D-半乳糖共孵育的方法诱导细胞衰老,β-半乳糖苷酶染色和透射电镜鉴定衰老VSMC;VSMC随机分成对照组、D-半乳糖组、Rg3高浓度组、Rg3低浓度组,Western blot方法检测p16、p21和p53蛋白的表达水平,流式细胞术检测细胞周期。结果与对照组比较,D-半乳糖组β-半乳糖苷酶阳性细胞明显升高[(58.67±2.52)%vs(4.67±0.58)%,P<0.05]。电镜下表现为细胞核膜内折,细胞线粒体肿胀,脂褐素堆积;p16、p21和p53蛋白表达水平明显升高(P<0.05),细胞周期停滞在G0/G1期。与D-半乳糖组比较,Rg3低浓度组和Rg3高浓度组β-半乳糖苷酶阳性细胞明显减少,p16、p21和p53蛋白表达水平明显降低,G0/G1期细胞数明显减少(P<0.05)。结论人参皂甙Rg3可抑制VSMC衰老,其机制可能部分通过抑制细胞生长周期p16INK4a/Rb、p53-p21Cip1/Waf1信号通路来实现。     

松花粉抗成纤维细胞复制性衰老的机制

目的 研究松花粉对衰老成纤维单细胞面积、β-半乳糖苷酶染色(SA-β-gal)阳性率、p16INK4A和p21CIP-1表达以及细胞周期的影响.方法 以二倍体成纤维(2BS)细胞建立衰老细胞模型.生物体视学法分析单细胞面积变化;免疫组化法测SA-β-gal阳性率;流式细胞术分析细胞周期;RT-PCR法测定p16INK4A、p21CIP-1基因mRNA表达量.结果 56代细胞出现典型的衰老细胞形态改变,同时SA-β-gal染色阳性率与G1期细胞比例均增高.经松花粉处理后,衰老细胞的单细胞面积、SA-β-gal染色阳性率与G1期细胞比例均显著减少(P＜0.05);p16INK4A与p21CIP-1mRNA的表达量均较衰老模型组明显下调(P＜0.05). 结论松花粉具有改善细胞复制性衰老的作用,其分子机制可能与下调p16INK4A及p21CIP-1基因mRNA的表达从而改善衰老细胞G1期阻滞有关.     

AngⅡ诱导血管内皮细胞衰老相关基因表达的研究

目的 探讨血管紧张索Ⅱ(AngⅡ)诱导人脐静脉内皮细胞(HUVECs)衰老相关基因p16INK4a、p21cip1的表达.方法 体外培养HU-VECs并予AngⅡ(10-6mol/L)干预,采用光镜观察细胞形态学改变,β-半乳糖苷酶(β-gal)染色和流式细胞术鉴定细胞衰老,并利用免疫细胞化学染色法分析Ang Ⅱ诱导HUVECs 0、12、24、36、48 h的p16INK4a阳性细胞表达率,Western印迹法分析AngⅡ诱导HUVECs 0、12、24、36、48 h的p16INK4a、p21cip1蛋白表达的时间效应关系.结果 AngⅡ诱导组HUVECs出现典型的细胞体积增大,形态不规则;约80%的细胞呈现β-gal阳性染色(80.10±6.81)%,流式细胞仪检测细胞周期停滞于G0/G1(91.36±6.45)%,证实细胞衰老;AngⅡ呈时间依赖性上调p16IK4a、p21cip1蛋白表达.结论 AngⅡ诱导血管内皮细胞衰老的分子机制之一可能与上调衰老细胞内细胞周期蛋白p16INK4a、p21cip1的表达,使细胞周期停滞于G1期有关.     

血管紧张素(1-7)通过p53/Drp1轴对血管紧张素Ⅱ诱导的血管内皮细胞衰老的影响

目的 观察血管紧张素(1-7)[Ang(1-7)]对血管紧张素Ⅱ(AngⅡ)诱导的人脐静脉内皮细胞(HUVEC)衰老的作用及机制。方法 体外用含有10%胎牛血清(FBS)的DMEM培养基培养HUVEC 48 h,随机分为对照组、Ang(1-7)组(1 μmol/L)、AngⅡ组(1 μmol/L)和AngⅡ＋Ang(1-7)组。通过细胞衰老β-半乳糖苷酶(SA-β-Gal)染色试剂盒检测各组衰老细胞数量(光学显微镜观察),通过活性氧检测试剂盒测定各组细胞活性氧(ROS)的水平,通过Western blot检测各组细胞p53和动力蛋白相关蛋白1(Drp1)的表达。结果 与对照组比较,AngⅡ组SA-β-Gal染色阳性细胞明显增多(P＜0.001),细胞ROS水平增加(P＜0.001),p53及Drp1蛋白表达量明显增加(P＜0.01)。与AngⅡ组比较,AngⅡ＋Ang(1-7)组SA-β-Gal染色阳性细胞率(P＜0.01)、细胞ROS水平(P＜0.001)、p53及Drp1蛋白表达量(P＜0.05)均降低。结论 Ang(1-7)可能通过影响p53/Drp1通路,抑制HUVEC内ROS生成,减轻AngⅡ诱导的HUVEC衰老。     

烟酰胺单核苷酸对D-半乳糖诱导肾脏衰老的作用研究

目的 探讨烟酰胺单核苷酸(NMN)对D-半乳糖(D-gal)诱导小鼠肾脏衰老的作用及其可能的抗炎机制。方法 将24只雄性C57BL/6小鼠随机分为4组:对照组、NMN组、D-gal组与D-gal+NMN组。采用皮下注射D-gal的方法构建肾脏衰老模型。记录各组小鼠体质量；采用苏木精-伊红(HE)和马松(Masson)染色观察小鼠肾脏病理损伤和纤维化；应用衰老相关β-半乳糖苷酶(SA-β-gal)染色评估组织衰老水平；使用免疫组化法(IHC)和蛋白免疫印迹法(Western blot)观察衰老指标p16、p21的定位及表达；使用Western blot测定抗衰老蛋白沉默信息调节因子1(SIRT1)及炎症指标肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、核因子-κB(NF-κB)的表达水平。采用SPSS 26.0统计软件进行数据分析。根据数据类型,分别采用单因素方差分析、LSD-t检验或Kruskal-Wallis检验进行组间比较。结果 NMN对D-gal组小鼠体质量未产生显著影响(P>0.05)。与对照组比较,D-gal组肾脏出现肾小球萎缩,肾小管肿胀、扩张和间质纤维化改变。IHC结果示p16、p21表达增加,并且主要位于肾小管,同时可见SA-β-gal阳性率增加,差异有统计学意义(P<0.05)。Western blot结果示D-gal组肾脏衰老蛋白p16、p21及炎症指标TNF-α、IL-1β、NF-κB表达上调,而抗衰老蛋白SIRT1表达下调,差异有统计学意义(P<0.05)。NMN处理后,D-gal组肾小球萎缩,肾小管肿胀、扩张及间质纤维化程度明显降低,衰老及炎症指标显著下降,此外,SIRT1下调及SA-β-gal阳性率增加均得到缓解,差异均有统计学意义(P<0.05)。结论 NMN可能通过促进SIRT1表达和抑制NF-κB途径介导的炎症反应,延缓D-gal诱导的肾脏衰老。     

白藜芦醇对亚急性衰老雄性小鼠生殖功能的作用

目的 探讨一定剂量的白藜芦醇对D-半乳糖所致亚急性衰老模型小鼠生殖系统的作用.方法 将30只C57小鼠随机分为6组:生理盐水组(NS);DMSO溶剂对照组(DMSO);D-半乳糖模型组(D-gal);低剂量白藜芦醇处理组(RES-L);高剂量白藜芦醇处理组(RES-H);维生素C阳性对照组(VC).给予D-半乳糖皮下注射和白藜芦醇灌胃后观察小鼠睾丸脏器指数,精子质量(包括精子密度,精子活力,精子活率,精子畸形率)以及血清SOD、MDA和血清睾酮水平(T)的变化及睾丸石蜡切片的HE染色和p53免疫组化.结果 各组之间睾丸脏器指数无明显变化;与D-gal组相比较,RES-H组小鼠精子密度升高,精子活率增加,精子活力增加,精子畸形率降低,小鼠血清T水平升高,血清SOD活力升高,血清MDA降低;睾丸石蜡切片HE染色见生精细胞减少,p53阳性细胞增加.结论 白藜芦醇对D-半乳糖所致亚急性衰老小鼠生殖系统功能有保护作用.     

人参皂苷Rg1对衰老大鼠胸腺结构与功能的影响

目的探讨人参皂苷Rg1对衰老大鼠胸腺结构与功能的影响及机制。方法 SD大鼠随机分为4组,每组10只。衰老模型组,皮下注射D-半乳糖120 mg/kg,1次/d,42 d;Rg1衰老模型组,注射D-半乳糖剂量与时间同衰老模型组,第15天起腹腔注射Rg1 20 mg/kg,1次/d,28 d正常对照组,皮下注射生理盐水1次/d,42 d;Rg1正常对照组,注射生理盐水1次/d,14 d,第15天起腹腔注射Rg1(同Rg1衰老模型组)。模型复制或药物注射完成后第2天,取胸腺测定胸腺指数,石蜡切片观察胸腺形态学;衰老相关β-半乳糖苷酶(SA-β-Gal)染色检测胸腺细胞衰老,CCK-8检测胸腺细胞对刀豆蛋白A刺激的增殖能力,ELISA检测胸腺细胞分泌肿瘤坏死因子(TNF)-α、GM-CSF、白细胞介素(IL)-2与IL-6的能力,流式细胞术检测细胞活性氧(ROS)、胸腺细胞凋亡,硫代巴比妥酸法检测丙二醛(MDA),酶学检测超氧化物歧化酶(SOD),DTNB法测定谷胱甘肽(GSH)、氧化谷胱甘肽(GSSG)含量,Western印迹检测细胞衰老相关蛋白p21、p53、Rb的变化。结果 Rg1衰老模型组大鼠胸腺指数升高、胸腺皮质面积比例增加、胸腺细胞的增殖能力提高,凋亡率减少、SA-β-Gal阳性胸腺细胞百分率下降、TNF-α、GM-CSF、IL-2、IL-6的分泌能力明显提高、SOD活性明显提升;ROS和MDA含量下降;p53、p21、Rb蛋白表达有显著下调。结论 D-半乳糖复制的衰老模型大鼠胸腺结构与功能损伤明显,人参皂苷Rg1对其致衰损伤有明确的保护作用,其机制可能与抑制氧化损伤和下调p16-Rb、p53/p21信号通路有关。     

构建P16慢病毒载体永生化心肌干细胞的探讨

目的：构建P16慢病毒载体,为修复坏死心肌干细胞提供理论基础。方法构建 pLVX p16ink4a ZsGreen、pLVX P16INK4a慢病毒载体,将P16目的基因转导入目标细胞。利用倒置免疫荧光显微镜观察携带绿色荧光蛋白的 pLVX p16ink4a ZsGreen阳性转导细胞的变化,并通过β半乳糖苷酶染色鉴定观察 pLVX P16INK4a 转导阳性细胞即衰老细胞的变化。利用Western blotting法测定P16目的基因转导成功后蛋白变化水平。结果携带绿色荧光蛋白的 pLVX P16ink4a ZsGreen阳性转导细胞传代增殖受到抑制,β半乳糖苷酶染色鉴定观察 pLVX P16INK4a转导阳性细胞即衰老细胞增殖受到抑制,上述两种阳性转导细胞在细胞培养传代过程中被稀释。Western blotting法测定p16INK4a蛋白水平也存在稀释变化。结论构建P16慢病毒载体转导目标细胞传代培养过程中,目的基因P16在细胞传代增殖过程中存在抑制作用,并可导致转导阳性细胞稀释。     

雄激素对雄性大鼠心脏衰老相关的β-半乳糖苷酶的影响

目的 观察补充外源性睾酮及给予雄激素受体阻断剂后对衰老相关p-半乳糖苷酶（ SA-β-Gal）的影响,探讨雄激素与心脏衰老的关系.方法 雄性Wistar大鼠40只随机分为去势组（10只）、补充睾酮组（去势＋生理剂量睾酮组,10只）、氟他胺组（去势＋生理剂量睾酮＋氟他胺组,10只）、假手术组（10只）.干预8周后测定各组血浆睾酮浓度,取心肌组织用HE染色观察心肌组织学变化;组织化学染色观察心肌组织细胞SA-β-Gal的活性.结果 较假手术组睾酮浓度,氟他胺组升高近3倍（P＜0.01）;与假手术组比较,去势组SA-p-Gal活性明显增强[（2.0±0.9）vs（1.2±0.7）,P＜0.01];与去势组比较,生理剂量补充睾酮组SA-β-Gal活性（0.9±0.8）明显减弱（P＜0.01）;与单纯补充生理剂量睾酮组比较,氟他胺组SA- β-Gal活性（2.1±0.8）反而增强（P＜0.01）;补充生理剂量睾酮组与假手术组SA-β-Gal的活性相比差异无统计学意义（P=0.309）.结论 雄激素缺乏可能影响雄性大鼠心肌组织中SA-β-Gal的活性,提示心脏老化可能与雄激素水平相关.     

叶酸对健康人外周血单个核细胞肿瘤相关基因甲基化状态的影响

目的 探讨叶酸干预对健康人外周血单个核细胞中肿瘤相关基因启动子甲基化状态的影响.方法 健康志愿者10人,均分为2组,分别口服叶酸5 mg或安慰剂,每日1次,连续3个月.于干预前后,以化学发光酶免疫分析试剂盒测定血清叶酸浓度,亚硫酸氢钠测序PCR(BSP)技术分别检测癌基因c-myc、c-Ha-ras,抑癌基因E-cadherin、p16INK4A和错配修复基因hMLH1的启动子甲基化状态.结果 叶酸干预后,干预组血清叶酸水平显著升高(T=-4.739,P<0.05),而对照组无明显变化.叶酸干预3个月后,癌基因c-myc启动子甲基化率分别从干预前的4%、服用1周时的3.3%、服用1个月时的4.1%增加到8%(t=-4.079,P<0.05),而服用安慰剂者无明显变化.叶酸干预前后,其他肿瘤相关基因包括c-Ha-ras、E-cadlherin、p16INK4A和hMLH1的启动子甲基化水平无明显改变.结论 叶酸干预可升高癌基因c-myc启动子甲基化水平,但不影响抑癌基因E-cadlherin、p16INK4A和hMLH1的甲基化状态.

Abstract：

Objective To investigate the effect of folic acid on the DNA methylation of tumorrelated genes promoters in healthy human peripheral blood mononuclear cells(PBMC). Methods Ten healthy volunteers were divided into two groups, and were randomized to receive either 5 mg folic acid (n=5)or placebo(n = 5) , one time per day for 3 months. The serum folic acid concentration was detected with chemiluminescence enzyme immunoassay kit before and after the intervention. The methylation statuses of five tumor-related genes promoter, including oncogenes c-myc, c-Ha-ras,tumor suppressor genes p16INK4A, E-cadherin and mismatch repair gene hMLH1 in PBMC were detected by bisufite sequencing. Results After folic acid intervention, the level of serum folic acid increased significantly in intervention group (t= -4. 739,P<0. 05) , however no significant difference in control group. After three-month folic acid intervention, the level of methylation of oncogene c-myc promoter increased from 4%, 3. 3%, 4. 1% before intervention, one week after intervention, one month after intervention respectively to 8%(t= -4. 079,P<0. 05), while no significant change in placebo taken group. Before and after the folic acid intervention, there was no significant difference of DNA methylation of other tumor-related genes promoter, including c-Ha-ras、E-cadherin、p16INK4Aand hMLH1. Conclusion Folic acid intervention can up-regulate DNA methylation of oncogene c-myc promoter, but can not affect the promoter methylation status of tumor suppressor genes E-cadherin,p16INK4Aand hMLH1.     

Histone deacetylase inhibitor suppression of autoantibody-mediated arthritis in mice via regulation of p16INK4a and p21(WAF1/Cip1) expression

OBJECTIVE: To examine whether depsipeptide (FK228), a histone deacetylase (HDA) inhibitor, has inhibitory effects on the proliferation of synovial fibroblasts from rheumatoid arthritis (RA) patients, and to examine the effects of systemic administration of FK228 in an animal model of arthritis. METHODS: Autoantibody-mediated arthritis (AMA) was induced in 19 male DBA/1 mice (6-7 weeks old); 10 of them were treated by intravenous administration of FK228 (2.5 mg/kg), and 9 were used as controls. The effects of FK228 were examined by radiographic, histologic, and immunohistochemical analyses and arthritis scores. RA synovial fibroblasts (RASFs) were obtained at the time of joint replacement surgery. In vitro effects of FK228 on cell proliferation were assessed by MTT assay. Cell morphology was examined by light and transmission electron microscopy. The effects on the expression of the cell cycle regulators p16INK4a and p21(WAF1/Cip1) were examined by real-time polymerase chain reaction and Western blot analysis. The acetylation status of the promoter regions of p16INK4a and p21(WAF1/Cip1) were determined by chromatin immunoprecipitation assay. RESULTS: A single intravenous injection of FK228 (2.5 mg/ml) successfully inhibited joint swelling, synovial inflammation, and subsequent bone and cartilage destruction in mice with AMA. FK228 treatment induced histone hyperacetylation in the synovial cells and decreased the levels of tumor necrosis factor alpha and interleukin-1beta in the synovial tissues of mice with AMA. FK228 inhibited the in vitro proliferation of RASFs in a dose-dependent manner. Treatment of cells with FK228 induced the expression of p16INK4a and up-regulated the expression of p21(WAF1/Cip1). These effects of FK228 on p16INK4a and p21(WAF1/Cip1) were related to the acetylation of the promoter region of the genes. CONCLUSION: Our findings strongly suggest that systemic administration of HDA inhibitors may represent a novel therapeutic target in RA by means of cell cycle arrest in RASFs via induction of p16INK4a expression and increase in p21(WAF1/Cip1) expression.     

Value of mink vomit model in study of anti-emetic drugs

AIM: To establish a new, reliable vomit model of minks. METHODS: Adult male minks were randomly divided into 8 groups (n=6): cisplatin (7.5 mg/kg) intraperitoneal injection (i.p.) group, copper sulfate (40 mg/kg) intragastric injection (i.g.) group, apomorphine (1.6 mg/kg) subcutaneous injection (s.c.) group, and 18 Gy whole-body X-irradiation group, ondansetron injection group (2 mg/kg i.p.) 30 min later followed by cisplatin (7.5 mg/kg) i.p., normal saline (NS) i.p. injection control group, metoclopramide injection group (4 mg/kg i.p.) 30 min later followed by apomorphine (1.6 mg/kg) s.c., NS i.g. control group. The frequency of retching and vomiting was calculated. After behavioral experiment, distribution of 5-HT in the ileum was detected by immunohistologic method. RESULTS: Cisplatin, apomorphine, copper sulfate and X-irradiation administered to minks evoked a profound emetic response in the animals. However, retching and vomiting were significantly inhibited by pretreatment with ondansetron and metoclopramide in cisplatin and copper sulfate groups (P=0.018). Immunohistologic result showed that 5-HT released from enterochromaffin cells (EC cells) was involved in vomiting mechanism. CONCLUSION: Mink vomit model has a great value in studying the vomiting mechanism and screening new antiemetic drugs.     

Co-transfection of p16(INK4a) and p53 genes into the K562 cell line inhibits cell proliferation

BACKGROUND AND OBJECTIVES: The tumor suppressor genes p53 and p16(INK4a), both of which act in tumor surveillance, are homozygously deleted in the human leukemia cell line K562. This study was performed to assess whether co-transfection of the p16(INK4a) and p53 genes could inhibit K562 cell proliferation. DESIGN AND METHODS: p16(INK4a) and p53 genes were co-transfected into K562 cells with liposome, and the expression of the transfected genes was detected by Western-immunoblotting and immunocytochemistry. The effect of the p16(INK4a) and p53 transfected cell culture was quantified by trypan blue staining, and the number of recovered viable cells was assessed every day after transfection. Cells were analyzed for expression of annexin V in order to detect apoptosis. Differentiation of transfected K562 cells was measured by the benzidine oxidation test, and the cell cycle was analyzed by flow cytometry. RESULTS: After co-transfection, there were 23% and 28% p53 and p16(INK4a) positive cells respectively. Co-transfection with p16(INK4a) and p53 genes significantly inhibited cell proliferation when compared to transfection with either p16(INK4a) or p53 gene. The percentage of cells expressing the apoptosis-related cell surface antigen annexin V was significantly higher in p53 and p16(INK4a) transfected cells than in p53 or p16(INK4a) transfected cells (6.24+/-0.37% vs 4.88+/- 0.17%, p<0.05 and vs 2.78+/-0.26%, p<0.05, respectively). p16(INK4a) and p53 co-transfection significantly increased the number of cells in G1 phase and decreased that in S phase. INTERPRETATION AND CONCLUSIONS: Expression of wild-type p16(INK4a) and p53 genes in K562 cells results in reduced proliferation and apoptosis. Introduction of exogenous p16(INK4a) and p53 genes into K562 cells might contribute to the clinical treatment of leukemia.     

Progesterone and testosterone in combination act in the hypothalamus of castrated rams to regulate the secretion of LH

We tested the hypotheses that progesterone enhances the negative feedback actions of testosterone in rams and that this occurs through actions at the hypothalamus. In the first part of this study, blood samples were collected every 10 min for 12 h before and after 7 days of treatment (i.m.) of castrated Romney Marsh rams (n=5 per group) with vehicle, progesterone (4 mg/12 h), testosterone (4 mg/12 h) or a combination of progesterone (4 mg/12 h) and testosterone (4 mg/12 h). In the second part of this study the brains of four gonad-intact Romney Marsh rams were collected, the hypothalamus was sectioned and in situ hybridisation of mRNA for progesterone receptors conducted. After 7 days of treatment with vehicle or progesterone or testosterone alone, there were no changes in the secretion of LH. In contrast, treatment with a combination of progesterone and testosterone resulted in a significant (P<0.01, repeated measures ANOVA) decrease in mean plasma concentrations of LH, the number of LH pulses per hour and the pre-LH pulse nadir and a significant (P<0.01) increase in the inter-LH pulse interval. We found cells containing mRNA for progesterone receptors throughout the hypothalamus, including the preoptic area (where most GnRH neurons are located in sheep), the periventricular, ventromedial and arcuate nuclei and the bed nucleus of the stria terminalis. This study shows that progesterone is capable of acting centrally with testosterone to suppress the secretion of LH in castrated rams and that cells containing mRNA for progesterone receptors are located in the hypothalamus of rams in the vicinity of GnRH neurons.     

艾灸神阙穴对衰老模型小鼠脑组织凋亡相关因子bcl-2、bax、caspase-3和p53表达的影响

目的研究艾灸神阙穴对衰老模型小鼠脑组织凋亡相关因子B淋巴细胞瘤-2基因(bcl-2)、bcl-2相关的X基因(bax)、含半胱氨酸的天冬氨酸蛋白水解酶(caspase)-3和p53蛋白表达的影响,探讨艾灸神阙穴延缓衰老的作用机制。方法健康2月龄昆明雄性小鼠,将其随机分为青年组、衰老模型组、艾灸组;青年组不做任何处理,衰老模型组和艾灸组每日颈背部皮下注射D-半乳糖120 mg/kg,连续注射42 d;艾灸组从模型复制的第15天起开始对神阙穴进行施灸,每次灸15 min,每日1次,每周连续施灸5 d后休息2 d再灸,连续4 w。艾灸结束后取出各组小鼠脑组织,采用Western印迹法检测小鼠脑组织bcl-2、bax、caspase-3和p53的蛋白表达。结果与青年组比,衰老模型组bcl-2蛋白表达显著降低(P<0.001),bax、caspase-3和p53的蛋白表达均显著升高(P<0.001,P<0.05);与衰老模型组比,艾灸组bcl-2蛋白表达显著升高(P<0.001),bax、caspase-3和p53的蛋白表达均显著降低(P<0.01,P<0.05)。结论艾灸神阙穴能延缓D-半乳糖所致衰老模型小鼠的衰老,其作用机制可能与调节脑组织bcl-2、bax、caspase-3和p53的蛋白表达有关。     

猕猴桃籽油抗衰老作用的实验研究

目的探讨猕猴桃籽油延缓衰老的作用机理。方法30只SD大鼠随机分为3组。对照组:每鼠每日灌服生理盐水和背部皮下注射150mg/kg生理盐水;模型组:每鼠每日灌服生理盐水和背部皮下注射150mg/kg125%D-半乳糖溶液;猕猴桃籽油干预组:每鼠每日灌服猕猴桃籽油0.670g/kg和背部皮下注射150mg/kg25%D-半乳糖溶液;每组时间均为8w。8w后测定各组血清超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量及皮肤组织羟脯氨酸的含量。结果与模型组相比,干预组SOD活性增高,MDA含量则显著下降,皮肤羟脯氨酸含量提高,差异均具有显著性(P<0.05)。结论猕猴桃籽油可通过SOD、MDA及羟脯氨酸的调节而起到延缓衰老的作用。     

The effect of N-nitro-L-arginine methyl ester on morphine-induced changes in the plasma corticosterone and testosterone levels in mice.

Effects of the nitric oxide synthase inhibitor, N-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg i.p.), on morphine-induced changes in the plasma corticosterone and testosterone levels were studied in male mice. Acute morphine administration (15 and 30 mg/kg i.p.) enhanced the corticosterone level after 1 and 2 hr (at a dose of 30 mg/kg only). A 4-day treatment with increasing doses of morphine, from 15 to 50 mg/kg i.p., increased the plasma corticosterone concentration at 2 hr after the last injection. Single administration of L-NAME (30 mg/kg i.p.) had no effect on the corticosterone level, whereas its repeated injections (30 mg/kg i.p., twice a day for four days) elevated the hormone concentration at 2 hr after the last dose. Pretreatment of mice with L-NAME enhanced the stimulatory effects of both acute and repeated morphine administration on the corticosterone level. D-NAME (30 mg/kg i.p.), an inactive form of the nitric oxide synthase inhibitor, had no effect on the morphine-induced changes in the corticosterone level. Acute morphine administration had no effect on the plasma testosterone level after 1 or 2 hr, whereas repeated drug injections decreased the hormone concentration after 2 hr. Single or repeated L-NAME administration did not influence the testosterone level in either control or morphine-treated animals. The above results indicate that inhibition of nitric oxide synthase enhances the stimulatory effect of morphine on corticosterone secretion, but does not influence the inhibitory effect of repeated morphine on the plasma testosterone concentration in mice.