DLPME-HPLC法同时测定人血清中维生素A和维生素E含量

目的 建立分散液相微萃取（DLPME）-高效液相色谱（HPLC）同时测定人血清中维生素A、E含量的方法。方法 2018年5月随机抽取人血液样本50例,经DLPME技术处理后,采用HPLC对人血清中维生素A、E含量进行检测,使用标准曲线法进行定量分析。结果 维生素A标准曲线方程为y=13225x+410.03,相关系数为0.9998,检出限为0.042 μg/ml;维生素E标准曲线方程为y=1383.9x-458.27,相关系数为0.9997,检出限为0.096 μg/ml。维生素A和维生素E的加标回收率分别为90.12%~103.70%和81.09%~92.21%,含量范围分别为（0.62±0.04）μg/ml和（8.41±0.43）μg/ml。结论 DLPME-HPLC法操作简便,节约试剂,对样本富集效率高,通过该方法的研究,对微量血清中维生素A和维生素E的测定具很好的的应用价值。     

浅谈高效液相色谱法同时测定钙镁D片中维生素D2和维生素D3的含量

目的 用高效液相色谱法同时测定钙镁D片中维生素D2和维生素D3的含量.方法 采用Kromsil C18反相色谱分离柱,流动相为甲醇-乙腈(90∶10),检测波长为270nm,流速为0.75ml/min,并且加入维生素A和维生素E进行干扰试验.结果 维生素D2、D3在0.8～98mg/L浓度范围内线性关系良好,维生素A和维生素E不干扰测定.结论 本方法对于测定片剂中的维生素D2和维生素D3具有简单,易于操作,分离效果好,结果准确的优点,适宜推广使用.     

浅谈高效液相色谱法同时测定钙镁D片中维生素D2和维生素D3的含量

目的用高效液相色谱法同时测定钙镁D片中维生素D2和维生素D3的含量。方法采用Kromasil C18反相色谱分离柱,流动相为甲醇-乙腈（90：10）,检测波长为270nm,流速为0.75ml/min,并且加入维生素A和维生素E进行干扰试验。结果维生素D2、D3在0.8～98mg/L浓度范围内线性关系良好,维生素A和维生素E不干扰测定。结论本方法对于测定片剂中的维生素D2和维生素D3具有简单,易于操作,分离效果好,结果准确的优点,适宜推广使用。     

HPLC法同时测定人血浆中帕罗西汀和喹硫平浓度

目的 建立同时测定人血浆中帕罗西汀和喹硫平浓度的高效液相色谱( HPLC)法.方法 采用HPLC法进行测定:Inertsil ODS-C18柱(4.6×150mm,5μm)为色谱柱,流动相为乙腈-磷酸二氢钠(0.05 mol/L磷酸二氢钠)(39∶61),流速为1.0mL/m in,检测波长为210nm,柱温为40℃,以乙酸乙酯-二氯甲烷(体积比75∶25)为萃取剂.结果 帕罗西汀在10～640μ g/L、喹硫平在20 ～ 1200μg/L范围内峰面积与浓度呈良好线性关系,检测限分别为5μg/L,8μg/L.结论 该方法简单、快速、灵敏、准确,可用于临床帕罗西汀与喹硫平的血药浓度监测和药动学研究.     

高效液相色谱法测定人血浆中的盐酸替扎尼定含量

目的 :建立用高效液相色谱法快速检测盐酸替扎尼定血药浓度的方法。方法 :取血浆加 1mol·L 1NaOH ,混匀 ,加氯仿提取吹干 ,用流动相复溶进样 ;色谱柱SUNTEKR KromasilC1 85u粒径 ,1 5 0× 4.6mmID ;色谱条件 :A :乙睛 =1 0 0∶2 5 (A :水 -甲酸 -氨水 (2 8% ) =1 0 0∶5∶1 0 (V/V ,pH 8.5 0 ) ) ;流速 1 .0mL·min 1;紫外检测波长 3 1 8nm ,内标物为雷尼替丁。结果 :盐酸替扎尼定的保留时间为 6.9min ,雷尼替丁的保留时间为 8.2min ,检测的线性范围 0 .3 867～ 49.5 0 0 0ng·mL 1(r =0 .9982 )方法回收率大于 90 .78% (n =5 )日…     

HPLC法测定热敷散中阿魏酸的含量

目的 建立HPLC法测定热敷散中阿魏酸含量的方法.方法 采用Eclipse XDB-C18色谱柱,乙腈-0.085%磷酸溶液(17∶83)为流动相;流速1.0ml/min;检测波长316nm.结果 阿魏酸在0.0384～0.3456μg范围内线性关系良好(r=0.9999),平均回收率为98.48%,RSD=1.02%(n=6).结论 本方法操作简便,专属性强,结果准确,可用于热敷散的质量控制.     

盐酸丁咯地尔、维生素C对氟哌啶醇致阿尔茨海默病大鼠抗氧化酶表达作用的影响

目的观察和探讨盐酸丁咯地尔和维生素C对氟哌啶醇致阿尔茨海默病大鼠抗氧化酶表达作用的影响。方法雄性W istar大鼠40只,随机分为对照组、模型组、实验1组、实验2组。除对照组外,其余大鼠均用氟哌啶醇建立阿尔茨海默病(A lzhe im er D isease,AD)动物模型,实验1、2组还分别对应腹腔注射盐酸丁咯地尔注射液和维生素C注射液。用电跳台法观察各组大鼠行为学改变,测定各组大鼠血、肝、肾、海马、脑皮质超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)含量。结果与对照组、模型组比较,盐酸丁咯地尔注射液、维生素C注射液均能维持实验大鼠的学习记忆能力,并使实验大鼠多种组织的SOD、GSH-PX表达值显著升高,差异有非常显著性意义(P<0.001)。结论盐酸丁咯地尔、维生素C都有维持学习记忆能力和上调抗氧化酶表达作用,且在抗氧化效果上两者相当。     

盐酸西替利嗪片的人体药代动力学研究

目的 建立测定盐酸西替利嗪片的人体药代动力学研究.方法 采用高效液相色谱法,测定20名健康男性志愿者口服盐酸西替利嗪片的血浆药物浓度:结果盐酸西替利嗪半衰期为(7.42±1.50)h,达峰时间为(1.06±0.42)h,峰浓度为(0.46±0.10)μg/mL,滞后时间为(1.25±0.47)h.结论 高效液相色谱方法结果准确,灵敏度高,能满足盐酸西替利嗪人体药代动力学研究的需要,可广泛应用于临床.     

HPLC法测定溶栓通脉胶囊中山柰素的含量

目的建立HPLC法测定溶栓通脉胶囊中山柰素含量的方法。方法采用Eclipse XDB—C18色谱柱,甲醇-水（52：48）为流动相;流速1．0mlomin-1：检测波长367nm。结果山柰素在0．0586-1．465μg范围内线性关系良好（r=0．9999）,平均回收率为98．40％,IKSD=0.95％（n=6）。结论本方法操作简便,专属性强,结果准确,可用于溶栓通脉胶囊的质量控制。     

The effect of ascorbic acid on cutaneous and nasal response to histamine and allergen

The effect of ascorbic acid (AA) on the skin wheal and flare response to histamine and allergen and on the nasal response to allergen was evaluated in eight adults with seasonal allergic rhinitis. The above parameters were measured after 3 days of AA administration (2 gm/day) and again after 3 days of a similar-appearing lactose placebo. An additional study was conducted in which six subjects took 0 (placebo), 1, 2, and 4 gm/day of AA to determine the dose-response effect of AA on histamine skin tests. Overall there was no difference in skin or nasal reactivity between AA and placebo regimens. The findings in this study suggest that AA in relatively high doses would have no beneficial effects on symptoms resulting from allergen exposure and that AA in doses of up to 4 gm/day will not suppress the histamine skin response.     

Effects of ascorbic acid on high-GSH and normal-GSH dog erythrocytes (II)

Mechanisms of ascorbic acid uptake and oxidative effects were studied in dog erythrocytes with high GSH and normal GSH concentrations. It was noted that ascorbic acid enters dog erythrocytes very slowly in the reduced form compared with the oxidised form (DHA) and by a glucose-independent mechanism. In the absence of glucose, accumulation of ascorbic acid, GSH depletion and increased methaemoglobin formation occurred successively. Compared with erythrocytes with normal GSH levels, those with high GSH levels showed a greater accumulation and prolonged presence of ascorbic acid, considerable delay in GSH depletion and less methaemoglobin formation. This is due to there being a larger reserve of GSH in high-GSH cells, which is exhausted more slowly. GSH-depleted erythrocytes were no longer able to accumulate ascorbic acid. Hydrogen peroxide (H₂O₂) was found to be the sole reactive oxygen species responsible for oxidative effects of ascorbic acid, while superoxide (O ₂ ^– ), hydroxyl radical (OH) and metal ions had relatively minor roles. Overall, these results clearly imply that GSH is essential in accumulating ascorbic acid and resisting oxidative effects in dog erythrocytes and that cells with high GSH levels containing larger reserve of GSH have an advantage with regard to the accumulation of ascorbic acid and its function.     

Blood cholesterol profile in guineapigs: Effect of ascorbic acid ingestion on hypercholesterolemia induced by manganese deficiency or overdosage of an anti-thyroid agent in diet

Effects of ascorbic acid ingestion (0.25 g/day) on serum cholesterol and total lipid levels were compared in three hyperlipidemic guineapig models. The first model received a diet rich in atherogenic and thrombogenic agents (e.g. cholesterol, butter-fat, cholic acid, vitamin D₂ etc.). The second (hypothyroid) and third (deficient manganese) models were created by feeding excess propyl-thiouracil (a potent goitrogen) and low-level manganese without added dietary cholesterol. The extreme rapidity with which guineapigs of Wistar strain develop hypercholesterolemia and early atherosclerotic lesions makes them an attractive animal model for studying the early development of atherosclerosis in man.

Decreased serum and tissue cholesterol levels despite more dietary cholesterol and butter-fat indicate that ascorbic acid is a good hypolipidemic/hypocholesterolemic agent. As the lipid-lowering property of ascorbic acid is obliterated due to hypothyroidism, it is most probable that vitamin C may act through the thyroid gland. Interaction with thyroid hormones seems not unlikely for ascorbic acid under physiological conditions. Since ascorbic acid has been suggested to provide protection against atherosclerosis induced by atherogenic/thrombogenic agents and proved incoherent in the face of thyroid dysfunction and manganese deprivation, the precise relation of these effects to lipid metabolism warrants investigation in some other fields.     

Effects of ascorbic acid on high GSH and normal dog erythrocytes (I)

Dog erythrocytes with high GSH and normal GSH concentrations were compared under effects of ascorbic acid. In the presence of glucose, these two types of erythrocytes showed a similar increase in intracellular ascorbic acid without change in GSH levels. Addition of iron (Fe³⁺) to the incubation medium enhanced ascorbic acid accumulation. In the absence of glucose, GSH fell markedly in both types of erythrocyte and less ascorbic acid accumulated in normal GSH cells than high GSH cells. With iron, normal cells showed GSH depletion and marked methaemoglobin formation. Lipid peroxidation with ascorbic acid and iron increased at a similar rate in both types of erythrocyte and was inhibited by catalase. Ferricyanide reduction in both erythrocytes loaded with ascorbic acid were similar and increased with glucose or catalase. There was a high correlation between intracellular ascorbic acid content and ferricyanide reduction. These results suggest that high GSH and normal GSH dog erythrocytes have a similar capacity for accumulating ascorbic acid and for reducing ferricyanide. However, normal GSH erythrocytes are more susceptible to the oxidant effect of ascorbic acid than high GSH cells; this is probably due to a smaller GSH reserve, which is exhausted more rapidly under oxidative stress.     

抗坏血酸对癫痫大鼠海马分子伴侣介导的自噬激活的影响

目的: 探讨癫痫大鼠海马氧化应激反应和分子伴侣介导的自噬(chaperone-mediated autophagy,CMA)活性的变化,以及抗氧化剂抗坏血酸 (ascorbic acid, AA)神经保护作用的可能机制。方法: 实验大鼠分为空白对照组、癫痫24 h组、AA预处理癫痫组和AA对照组。应用RT-PCR和免疫印迹法检测海马组织2a型溶酶体相关膜蛋白(lysosome-associated membrane protein type 2a,LAMP2a)mRNA和蛋白的变化,采用化学法检测海马组织丙二醛(malondialdehyde, MDA)和超氧化物歧化酶(superoxide dismutase,SOD)的水平。结果: 癫痫组大鼠海马组织LAMP2a转录和合成明显高于空白对照组,MDA含量明显升高,而SOD的水平显著下降。AA预处理可显著减低癫痫大鼠海马LAMP2a的转录和合成,并明显降低MDA的含量,却显著提高SOD的水平。结论: 癫痫发作导致的海马损伤时存在CMA激活现象和显著的氧化应激反应;抗氧化剂AA通过抑制CMA活性和降低氧化应激反应来减轻癫痫发作中的海马损伤,具有神经保护作用。     

核黄素和抗坏血酸对脱氧雪腐镰刀菌烯醇诱导小鼠胸腺细胞凋亡和增殖抑制影响的研究

目的:探讨核黄素和抗坏血酸在体内对脱氧雪腐镰刀菌烯醇 (DON)诱发小鼠胸腺细胞凋亡的阻断作用。方法:采用动物实验,应用DNA琼脂糖凝胶电泳和流式细胞术检测方法分析核黄素和抗坏血酸预处理对DON诱导小鼠胸腺细胞凋亡和增殖抑制的影响。结果:FCM检测结果表明,4mg/kgDON可诱导小鼠胸腺细胞凋亡,其凋亡率为13.73%±1.53 %。核黄素 (1.25-10mg/kg)和抗坏血酸 (25-100mg/kg)预处理组小鼠胸腺细胞凋亡率均明显低于DON组 (P <0.05),但不同剂量核黄素和抗坏血酸预处理组间凋亡率无明显差异。DNA琼脂糖凝胶电泳结果亦证实,DON处理组细胞出现明显的凋亡特有的“梯状条带”,而核黄素和抗坏血酸预处理各组及生理盐水对照组细胞均未出现“梯状条带”。给予核黄素和抗坏血酸预处理的各DON处理组细胞增殖指数与DON处理组细胞增殖指数之间无明显差异。结论:核黄素和抗坏血酸均可一定程度抑制DON体内对小鼠胸腺细胞的致凋亡作用,但对DON抑制胸腺细胞增殖的作用无明显影响.     

维生素C,皮质醇对正常人外周血单核细胞抗原提呈功能的影响

取健康男性献血员的肝素抗凝新鲜静脉血,密度梯度离心获单个核细胞(MNC),借粘附法和尼龙毛柱分离法分别获高纯度的单核细胞(Mon)和T淋巴细胞(T)。将Mon预先与纯化蛋白衍生物(PPD)和不同浓度的维生素C(VC)、皮质醇(HC)、VC HC共育24小时后加入T,借~3H-TdR掺入的T细胞增殖反应观察Mon向T提呈PPD的能力。结果表明,VC(3.75mM)对Mon的抗原提呈功能(APF)有显著的促进作用(P<0.01);而HC(5μg/ml)则有显著的抑制作用(P<0.01);二者并用时(浓度同上),VC能完全对消HC对Mon APF的抑制作用(P>0.05)。结果提示,VC可增强机体的特异性免疫功能,且能对消HC抑制免疫的副作用。     

The role of ascorbic acid on titanium dioxide-induced genetic damage assessed by the comet assay and cytogenetic tests

Titanium dioxide (TiO₂) is used in several commercial products such as cosmetics, sunscreen, toothpaste and pharmaceuticals. However, some recent investigations have revealed that titanium particles generate potential harmful effects on the environment and humans. Because of its strong antioxidant activity, ascorbic acid (AA) is admitted to act as an anti-mutagenic agent. The present study was undertaken to investigate the protective effect of AA against TiO₂-induced genotoxicity. Sister chromatid exchange (SCE), micronucleus (MN) and the comet assays were used to assess TiO₂-induced genotoxicity and to establish the protective effects of AA. There were significant increases (P<0.05) in both SCE and MN frequencies of cultures treated with TiO₂ as compared to controls. However, co-application of AA (4.87 and 9.73 μM) and TiO₂ resulted in decreases of SCE and MN rates as compared to the group treated with titanium alone. Besides, significant reductions of primary DNA damage (comet assay) were determined when the AA was added to the cell culture medium simultaneously with TiO₂. In conclusion, the preventive role of AA in alleviating TiO₂-induced DNA damage was indicated for the first time in the present study.     

“In vitro” improvement of defective monocyte chemotaxis in intravenous drug abusers after incubation with ascorbic acid

Summary Intravenous drug abusers have a deficit of monocyte chemotaxis. In vitro ascorbic acid restores the impaired chemotaxis.Abbreviations CI Chemotactic index - EAS Endotoxin-activating serum - IDA Intravenous drug abusers - PBM Peripheral blood monocytes     

The protective role of ascorbic acid on hippocampal CA1 pyramidal neurons in a rat model of maternal lead exposure

Oxidative stress is a major pathogenic mechanism of lead neurotoxicity. The antioxidant ascorbic acid protects hippocampal pyramidal neurons against cell death during congenital lead exposure; however, critical functions like synaptic transmission, integration, and plasticity depend on preservation of dendritic and somal morphology. This study was designed to examine if ascorbic acid also protects neuronal morphology during developmental lead exposure. Timed pregnant rats were divided into four treatment groups: (1) control, (2) 100 mg/kg ascorbic acid once a day via gavage, (3) 0.05% lead acetate in drinking water, and (4) 0.05% lead + 100 mg/kg oral ascorbic acid. Brains of eight male pups (P25) per treatment group were processed for Golgi staining. Changes in hippocampal CA1 pyramidal neurons’ somal size were estimated by cross-sectional area and changes in dendritic arborization by Sholl’s analysis. One-way ANOVA was used to compare results among treatment groups. Lead-exposed pups exhibited a significant decrease in somal size compared to controls (P < 0.01) that was reversed by cotreatment with ascorbic acid. Sholl’s analysis revealed a significant increase in apical dendritic branch points near cell body (P < 0.05) and a decreased total dendritic length in both apical and basal dendritic trees of CA1 neurons (P < 0.05). Ascorbic acid significantly but only partially reversed the somal and dendritic damage caused by developmental lead exposure. Oxidative stress thus contributes to lead neurotoxicity but other pathogenic mechanisms are also involved.