绿茶多酚改善环孢素A抑制血管舒张的作用

Objective To observe the alleviation effect of green tea polyphenols (GTP) on cyclosporine A (CsA)-induced inhibition of vasodilation, and to study the underlying mechanism. Methods Thirty SD rats were randomly divided into three groups: CsA group, control group and CsA + GTP group. Five weeks after the treatment, the body weight, kidney function (BUN, Cr) of the rats were measured. Then thoracic aorta rings were mounted on a bath system, and the Ach-induced vasodilation, the effect of L-NAME and indomethacin pretreatment on the vasodilation and the denuded vasodilation were evaluated. The contents of nitric oxide (NO) in the vascular tissues were measured. Results Five weeks later, the body weight of the rats in CsA group (253.2 ±8.1) g was lighter than that in control group (292.1 ±9.5) g (P < 0.05);the body weight in CsA + GTP group (287.9 ± 9.7) g was heavier than that in CsA group ( P < 0.05);The levels of BUN and Cr in CsA group were higher than in control group (P <0.05);The levels of BUN and Cr in CsA + GTP group were lower than in CsA group (P <0.05). The maximal response for Achinduced vasodilation in CsA group was (42.5 ±4.3)% , significantly lower than (81.2 ±7. 6)% in control group and (70.1 ± 6.5) % in CsA + GTP group (both/P < 0.05). After pretreatment with L-NAME, the vasodilation in CsA group and CsA + GTP group was (40.3 ±3.7)% and (45.8 ±4.2)% respectively, lower than in control group (79. 4 ± 6. 8)% ;After pretreatment with indomethacin, the vasodilation in control group and CsA + GTP group was higher than in CsA group (both P < 0.05). The vasodilation in the denuded groups was inhibited, but there was no significant difference between groups (P>0.05). In CsA group, the content of NO in vascular tissues was lower than that in control group and CsA + GTP group (both P < 0.05). Conclusion CsA might decrease the NO content in vascular tissues and induce abnormal endothelium-dependent vasodilation which is mediated by NO. The administration of GTP could increase the NO content and alleviate the CsA-induced inhibition of the endothelium-dependent vasodilation.     

绿茶多酚改善环孢素A抑制血管舒张的作用

Objective To observe the alleviation effect of green tea polyphenols (GTP) on cyclosporine A (CsA)-induced inhibition of vasodilation, and to study the underlying mechanism. Methods Thirty SD rats were randomly divided into three groups: CsA group, control group and CsA + GTP group. Five weeks after the treatment, the body weight, kidney function (BUN, Cr) of the rats were measured. Then thoracic aorta rings were mounted on a bath system, and the Ach-induced vasodilation, the effect of L-NAME and indomethacin pretreatment on the vasodilation and the denuded vasodilation were evaluated. The contents of nitric oxide (NO) in the vascular tissues were measured. Results Five weeks later, the body weight of the rats in CsA group (253.2 ±8.1) g was lighter than that in control group (292.1 ±9.5) g (P < 0.05);the body weight in CsA + GTP group (287.9 ± 9.7) g was heavier than that in CsA group ( P < 0.05);The levels of BUN and Cr in CsA group were higher than in control group (P <0.05);The levels of BUN and Cr in CsA + GTP group were lower than in CsA group (P <0.05). The maximal response for Achinduced vasodilation in CsA group was (42.5 ±4.3)% , significantly lower than (81.2 ±7. 6)% in control group and (70.1 ± 6.5) % in CsA + GTP group (both/P < 0.05). After pretreatment with L-NAME, the vasodilation in CsA group and CsA + GTP group was (40.3 ±3.7)% and (45.8 ±4.2)% respectively, lower than in control group (79. 4 ± 6. 8)% ;After pretreatment with indomethacin, the vasodilation in control group and CsA + GTP group was higher than in CsA group (both P < 0.05). The vasodilation in the denuded groups was inhibited, but there was no significant difference between groups (P>0.05). In CsA group, the content of NO in vascular tissues was lower than that in control group and CsA + GTP group (both P < 0.05). Conclusion CsA might decrease the NO content in vascular tissues and induce abnormal endothelium-dependent vasodilation which is mediated by NO. The administration of GTP could increase the NO content and alleviate the CsA-induced inhibition of the endothelium-dependent vasodilation.     

环孢素A对成骨细胞分化的影响

目的　探讨环孢素A(CsA)对原代培养小鼠骨髓间质干细胞 (BMSCs)增殖及向成骨细胞分化的影响。方法　采用原代培养小鼠BMSCs模型 ,在培养液中加入不同浓度的CsA以及单独或联合使用左旋精氨酸 (L arginine)后 ,测定 [3 H] 甲基胸腺嘧啶 ([3 H] TdR)掺入率与细胞数 ,反映细胞增殖情况 ;测定碱性磷酸酶活性与钙沉积量 ,反映细胞向成骨细胞分化状态 ;用一氧化氮 (NO)试剂盒测定细胞培养基中NO释放量。结果　CsA呈剂量依赖性 (10 -6、3× 10 -6、6× 10 -6、10 -5mol/L)减少 [3 H] TdR掺入率 ;抑制细胞增殖 ;降低细胞碱性磷酸酶活性与钙沉积量 ;并伴随NO释放量减少。如果同时给予L arginine(10 -4mol/L) ,可完全逆转CsA(10 -6mol/L)的以上作用。结论　CsA可能通过抑制L arginine/NO通路而阻碍BMSCs增殖及向成骨细胞分化。     

环孢素A对吻合血管异体骨移植血管平滑肌细胞表型转变的影响

目的 通过研究环孢素A对吻合血管异体骨移植血管平滑肌细胞(VSMCs)表型改变的影响,探讨移植物血管动态变化的规律. 方法 建立兔吻合血管异体骨移植修复股骨大段缺损的模型,动物分为实验组(术后应用环孢素A)及对照组(术后未应用环孢素A),在不同时段取出移植物血管制作组织学切片,观察血管壁形态和结构变化,研究VSMCs的表型改变. 结果 实验组和对照组的供体血管都呈进行性狭窄,血管内膜逐渐增厚,但实验组血管壁增厚的速度明显慢于对照组.实验组血管平滑肌细胞收缩型标志蛋白α-肌动蛋白呈递减性表达;对照组也表现出同样的规律,但衰减速度明显快于实验组. 结论 吻合血管异体骨移植后移植物血管发生进行性狭窄;环孢素A能在一定程度上抑制VSMCs表型的转变,延长移植物通血时间.     

苯多酚减轻环孢素A急性肾毒性的作用及其机理研究

目的：探讨茶多酚（TP）减轻环孢素A（CsA)急性肾毒性的作用及其机制。方法：按照分组,分别给予大鼠橄榄油,TP,CsA及TP＋CsA,给药14d后,取血测尿素氮及血,尿肌酐,计算机酐清除率,以病理评分法记录肾脏损害程度,硫代巴比妥酸法（TBA法）测定大鼠肾组织的脂质过氧化水平,黄嘌氧化法测定肾组织超氧化物歧化酶（SOD）的活力,二硫代二硝基苯甲酸（DTNB）比色法测定谷胱甘肽过氧化物酶（GSH－Px)活力,结果P：使用CsA后14d,大鼠的肾脏可见明显损害,肌酐清除率明显下降,组织丙二醛（GSH－Px)活力,结果,使用CsA后14d,大鼠的肾脏可见明显损害,肌酐清除率明显下降,组织丙二醛（MDA）水平升高,SOD与GSH－Px活性下降,TP具有减轻CsA肾毒性的作用,结论：茶多酚能有效地减轻CsA所致的大鼠肾脏毒性,可能与其清除氧自由基,保护肾组织中SOD及GSH－Px活性有关。     

环孢素A的慢性肾毒性

环孢素Ａ的慢性肾毒性是影响临床同种肾移植术后病人长期存活的重要因素之一，其机理仍不清楚。目前研究认为，转化生长因子β等细胞因子在环孢素Ａ慢性肾毒性发病中起重要的作用。本文对这方面的研究作一综述。     

Protective effect of green tea polyphenols on bone loss in middle-aged female rats

SUMMARY: Recent studies have suggested that green tea polyphenols (GTP) are promising agents for preventing bone loss in women. Findings that GTP supplementation resulted in increased urinary GTP concentrations and bone mass via an increase of antioxidant capacity and/or a decrease of oxidative stress damage suggest a significant role of GTP in bone health of women. INTRODUCTION: Recent studies suggested that green tea polyphenols (GTP) are promising agents for preventing bone loss in women. However, the mechanism related to the possible protective role of GTP in bone loss is not well understood. METHODS: This study evaluated bioavailability, mechanisms, bone mass, and safety of GTP in preventing bone loss in middle-aged rats without (sham, SH) and with ovariectomy (OVX). A 16-week study of 2 (SH vs. OVX) x 3 (no GTP, 0.1% GTP, and 0.5% GTP in drinking water) factorial design using 14-month-old female rats (n = 10/group) was performed. An additional 10 rats in baseline group were euthanized at the beginning of study to provide baseline parameters. RESULTS: There was no difference in femur bone mineral density between baseline and the SH+0.5% GTP group. Ovariectomy resulted in lower values for liver glutathione peroxidase activity, serum estradiol, and bone mineral density. GTP supplementation resulted in increased urinary epigallocatechin and epicatechin concentrations, liver glutathione peroxidase activity and femur bone mineral density, decreased urinary 8-hydroxy-2'-deoxyguanosine and urinary calcium levels, but no effect on serum estradiol and blood chemistry levels. CONCLUSION: We conclude that a bone-protective role of GTP may contribute to an increase of antioxidant capacity and/or a decrease of oxidative stress damage.     

Green tea polyphenols inhibit testosterone production in rat Leydig cells

This study investigated the acute effects of green tea extract （GTE） and its polyphenol constituents, （-）-epigallocatechin-3-gallate （EGCG） and （-）-epicatechin （EC）, on basal and stimulated testosterone production by rat Leydig cells in vitro. Leydig cells purified in a Percoll gradient were incubated for 3 h with GTE, EGCG or EC and the testosterone precursor androstenedione, in the presence or absence of either protein kinase A （PKA） or protein kinase C （PKC） activators. The reversibility of the effect was studied by pretreating cells for 15 min with GTE or EGCG, allowing them to recover for 1 h and challenging them for 2 h with human chorionic gonadotropin （hCG）, luteinizing hormone releasing hormone （LHRH）, 22（R）-hydroxycholesterol or androstenedione. GTE and EGCG, but not EC, inhibited both basal and kinase-stimulated testosterone production. Under the pretreatment conditions, the inhibitory effect of the higher concentration of GTE/EGCG on hCG/LHRH-stimulated or 22（R）- hydroxycholesterol-induced testosterone production was maintained, whereas androstenedione-supported testosterone production returned to control levels. At the lower concentration of GTE/EGCG, the inhibitory effect of these polyphenols on 22（R）-hydroxycholesterol-supported testosterone production was reversed. The inhibitory effects of GTE may be explained by the action of its principal component, EGCG, and the presence of a gallate group in its structure seems important for its high efficacy in inhibiting testosterone production. The mechanisms underlying the effects of GTE and EGCG involve the inhibition of the PKA/PKC signalling pathways, as well as the inhibition of P450 side-chain cleavage enzyme and 17β-hydroxysteroid dehydrogenase function.     

烧伤早期对大鼠一氧化氮及合成酶产生的影响

为探讨一氧化氮（ＮＯ）及其合成酶（ＮＯＳ）在烧伤早期的变化,作者采用雄性Ｗｉｓｔａｒ大鼠３５％Ⅲ度烫伤模型,于伤前、伤后八个时间点,分别测定血浆、皮肤创面及心、肺、肝、肾、肠五种脏器的ＮＯ含量及上述五种脏器内ＮＯＳ的活性单位。结果表明：（１）烧伤早期（７２小时）血浆ＮＯ含量值与伤前值比较有降低趋势（Ｐ＜０．０５,或０．０１）。（２）皮肤创面中检测的ＮＯ含量,伤前、伤后均超过血浆、五种脏器各自相应值的３．８～５７．８倍,且伤后３小时显著升高,尔后迅速降低呈低值水平,与伤前比较差异有显著意义（Ｐ＜０．０１）。（３）五种脏器的ＮＯ、ＮＯＳ含量值,伤后升高与降低的趋势基本一致,出现谷值与峰值时间也大致相同。这证实了ＮＯＳ做为合成ＮＯ前体酶含量变化一致性的诊断。而且推测烧伤后皮肤创面可能是导致产生ＮＯ的局部场所之一。     

绿茶对乳腺癌细胞血管内皮生长因子表达的影响及机制

目的 研究绿茶对人乳腺癌细胞株血管内皮生长因子(VEGF)表达的效应及其机制。方法 VEGF蛋白的测定采用酶联免疫吸附法；Northern印迹杂交法检测mRNA表达，含VEGF启动子的报告基因来检测VEGF转录活性。结果 绿茶有效成分在48h时分别抑制89．71％乳腺癌细胞细胞分泌的及33．93％细胞内合成的VEGF蛋白，48h抑制55．57％的VEGF转录活性，在24、48h绿茶成分可明显抑制VEGF的mRNA表达，激活蛋白—l(AP—1)的抑制剂抑制了VEGF的mRNA表达，绿茶有效成分可进一步增强这种抑制作用。结论 绿茶能够抑制乳腺癌细胞株VEGF水平的表达，这种抑制可能通过包括AP—l在内的多途径实现。     

环孢素A治疗儿童难治性肾病综合征26例疗效分析

目的探讨环孢素A治疗儿童难治性肾病综合征的临床疗效。方法 26例难治性肾病综合征患儿入院后口服环孢素A,剂量为2～4mg（/kg·d）,同时联合激素治疗,疗程3个月。治疗前及治疗后检测24h尿蛋白定量、血浆白蛋白、血浆胆固醇、尿素氮、血肌酐等指标。结果 26例患儿经治疗后,完全缓解14例,占53.85%;部分缓解10例,占38.46%;未缓解2例,占7.69%。结论环孢素A联合激素能有效治疗难治性肾病综合征。     

氟伐他汀对环孢素A所致大鼠成纤维细胞肾毒性的保护作用

目的 观察免疫抑制剂环孢素Ａ（CsA）对大鼠肾脏成纤维细胞增殖及细胞因子表达的影响以及氟伐他汀的干预作用，探讨氟伐他汀对CsA肾毒性的保护作用。 方法 体外培养大鼠肾脏成纤维细胞，四甲基偶氮唑盐（MTT）比色法测定CsA及氟伐他汀对细胞增殖的影响。RT-PCR方法检测转化生长因子β1（TGF-β1）、结缔组织生长因子（CTGF）及c-fos mRNA水平。Western印迹检测纤连蛋白(FN)的表达。 结果 CsA可明显抑制成纤维细胞增殖，且呈剂量和时间依赖效应（P < 0.05）。氟伐他汀与CsA合用后，对细胞增殖有明显的抑制作用（P < 0.01）。CsA刺激成纤维细胞TGF-β1、CTGF、c-fos及FN的产生（P < 0.05），氟伐他汀可下调这些改变（P < 0.05）。 结论 氟伐他汀可减轻CsA所致的大鼠肾脏成纤维细胞毒性     

茶多酚诱导膀胱癌T24细胞凋亡及上调PTEN表达

目的 探讨茶多酚（TP）抑制膀胱癌细胞生长的可能分子机制。方法 采用MTT法和流式细胞术，观察膀胱癌细胞系T24经不同浓度TP处理后细胞生长及PTEN蛋白表达的改变。结果TP以剂量依赖的方式抑制膀胱癌细胞的生长，加入0、50、100、200、400μg／mL TP的T24细胞抑制率分别为0％、11．2％、33.4％、36．9％、67．5％。流式细胞仪直方图上可见亚二倍体峰，癌细胞出现凋亡，凋亡率分别为6．8％、25．1％、28．6％、36．6％、41．1％；同时，随TP作用浓度的增加，G／S阻滞细胞逐渐增多，细胞分裂增殖指数（PI）降低；而细胞PTEN蛋白表达水平由（37.66±0．49）逐渐增加至（163．92±3．36）（P〈0．01）。结论 TP对T24细胞生长具有抑制作用，其机制可能是通过上调PTEN蛋白表达影响细胞周期和诱导细胞凋亡。     

绿茶饮液对大鼠膀胱肿瘤生长和间隙连接蛋白43表达的影响

目的观察绿茶对大鼠膀胱肿瘤生长和间隙连接蛋白43（Cx43）表达的影响。方法以N-丁基-N-（4-羟丁基）亚硝胺诱导形成大鼠膀胱癌动物模型。将39只成年雄性Wistar大白鼠随机分成正常对照组、膀胱癌模型组和绿茶组。24周后在麻醉下切除大鼠膀胱肿瘤组织并观察病理学改变，称量瘤体湿重并计算抑瘤率，免疫组织化学和DNA原位缺口末端标记法分别检测肿瘤微血管密度（MVD）和细胞凋亡指数（AI），半定量逆转录聚合酶链反应和Western印迹检测膀胱肿瘤组织Cx43mRNA及其蛋白的表达水平。结果绿茶组的膀胱肿瘤癌变发生率、瘤体湿重、MVD分别为38．46％（5／13）、（4．47±1．01）g、（2977±776），均显著低于模型组83．33％（10／12）、（5．63±1．27）g、（3708±570）（Χ^2=0．041、t=0．018、t=0．014，P均〈0．05），瘤重抑制率为20．82％；AI（22．46±2．90）％明显高于模型组（4．92±1．00）％（t=0．000，P〈0．01）。绿茶组的Cx43mRNA和蛋白的表达均极显著高于模型组（t=0．002、t=0．000，P均〈0．01）。结论绿茶能上调Cx43在大鼠膀胱肿瘤组织中的表达和增强Cx43介导的间隙连接通讯功能，从而有效抑制大鼠膀胱肿瘤的生长。