绿茶中维生素C氧化动力学模型研究

运用定温法和加速试验相结合的方法,对绿茶中维生素C氧化进行动力学分析研究,探讨通过维生素C的保留量预测绿茶保质期方法的可行性。研究中比较了动力学中常用的4种反应机理函数模式,通过试验与理论分析,得出线性最佳的三维扩散函数作为绿茶中维生素C的反应机理函数,获得了其前因子、活化能等动力学参数以及反应速率常数与温度的关系。研究结果为深入研究茶叶包装及其保质期预测提供了技术基础。     

维生素E修饰的透析膜抗氧化作用的临床研究

尿毒症本身代谢紊乱、血液透析相关因素及其它一些药物会促进慢性透析患者的氧化应激，致使透析相关的发病率以及病死率增加。本研究对比观察了口服VitE和采用VitE修饰透析膜的血透患者有关氧化应激指标，探讨及比较2者的抗氧化效果。     

保元抗癌口服溶液清除超氧自由基与DPPH作用

目的考察保元抗癌口服溶液对超氧自由基（O－2）和1,1 二苯基 2 苦肼自由基（DPPH）的清除作用。方法采用电子自旋共振（ESR）技术,以DPPH和 O－2为检测项目,测定保元抗癌口服溶液对自由基的清除效果。结果保元抗癌口服溶液稀释50倍时清除O－2和DPPH自由基分别为81.32%和98.47%。结论保元抗癌口服溶液对O－2和DPPH自由基均有较好清除作用,并呈一定的量效关系。     

花生衣红抗氧化活性的研究

花生衣是花生产品的副产物,经济价值低,但是含有大量的多酚物质.作者研究了从花生衣中提取的红色素对超氧阴离子(O2-.)、羟自由基(OH.)的清除作用及其对脂质过氧化物的阻抑作用.实验结果表明,花生衣红色素对超氧阴离子(O2-.)、羟自由基(OH.)有不同程度的清除作用,对脂质过氧化有明显的抑制,且呈剂量依赖关系.     

大鼠腹腔巨噬细胞释放自由基的直接检测及寒下药物对其影响

利用电子自旋共振法（ＥＳＲ）直接测定大鼠腹腔巨噬细胞经不同浓度内毒素刺激６０分钟后释放自由基水平的动态改变，及寒下药物清除自由基作用。结果表明，内毒素体外能诱使大鼠腹腔巨噬细胞产生自由基，并呈剂量依赖效应，随内毒素刺激剂量的增加，巨噬细胞产生自由基水平增高（Ｐ均＜０．０５）；以大承气汤为代表的寒下方剂能显著抑制大鼠腹腔巨噬细胞释放自由基（Ｐ＜０．０１），表明寒下方剂能清除自由基，抑制巨噬细胞呼吸爆发的产生。     

尿毒症,慢性肾炎患者血清维生素A,C,E的研究

本研究发现尿毒平病人的血清维生素Ａ含量为１２７．７０±６０．８０ｍｇ／Ｌ，显著高于正常对照组５８．０±１８．００μｇ／ｄｌ（Ｐ〈０．００１），维生素Ｅ含量则显著低于正常对照组（Ｐ〈０．０１）。维生素Ｃ含量与正常无显著性差别。慢怀肾炎组维生素Ａ为１１２．８１±６２．９３ｍｇ／Ｌ，显著高于正常对照组Ｐ〈０．０１），维生素Ｅ含量下正常无显著性差别。这对于指导临床用药及病人饮食营养有一定     

急性心肌梗死患者中性粒细胞氧自由基改变及维生素C的干预作用

目的 评价急性心肌梗死（AMI）患者中性粒细胞（PMN）氧化代谢功能以及维生素C的抗氧化损伤作用。方法 共有60例AMI患者被列入研究对象,随机分成两组,Ⅰ组（30例）给予AMI的常规治疗,Ⅱ组（30例）在常规治疗的基础上加用维生素C静脉滴注,每天3g ,连续应用7d后停药,在入院后第1,3,7,10天检测中性粒细胞化学发光（PMN－CL）参数,并行心电图检查,62例与AMI患者年龄性别匹配的健康人作为对照组（Ⅲ组）。结果 AMI患者PMN－CL各项参数显著性高于健康对照组。在第3、7天,Ⅱ组PMN－CL的各项参数较Ⅰ组明显下降,在偏旁 用维生素C后3d仍较Ⅰ组明显下降（P分别＜0.05,0.01,0.001）,心电图ST段改善的积分明显高于Ⅰ组。结论 AMI患者PMN产生大量的氧自由基（OFR）,造成机体氧化损伤;静脉滴注维生素C能有效抑制AMI患者PMN产生OFR,从而能减轻AMI患者心肌的进一步坏死。     

Experimental Myoglobinuric Acute Renal Failure: The Effect of Vitamin C

During times of war and natural disasters, rhabdomyolysis-induced myoglobinuric acute renal failure (ARF) can assume epidemic proportions. Free radicals play an important role in the pathogenesis of myoglobinuric ARF. Vitamin C is a major antioxidant, scavenging free radicals. We have not found any studies on the effect of vitamin C on myoglobinuric ARF. Thus, we aimed to investigate the effects of vitamin C on the myoglobinuric ARF formed by glycerol in rats. Three groups of rats were employed in this study. Group 1 served as control, group 2 was given 50% glycerol (10 mL/kg, i.m.), and group 3 was given glycerol plus vitamin C (20 mg/kg, i.p. for four days). Ninety-six hours after glycerol injections, blood samples and kidney tissues were taken from the anesthetized rats. Urea and creatinine levels in plasma; N-acetyl-beta-D-glucosaminidase activity in urine; malondialdehyde levels, superoxide dismutase and catalase enzyme activity in kidney tissue were determined. Histopathological changes and iron accumulation in the kidney tissue were evaluated. In this study, glycerol administration led to marked renal oxidative stress and severe renal functional and morphological deterioration. The treatment of animals with vitamin C partially corrected the renal dysfunction and morphological impairment. In this respect, vitamin C appears to be a promising candidate for the prevention of rhabdomyolysis-induced ARF. Higher dosages of vitamin C than in 20 mg/kg may be beneficial for better functional and morphological recovery in this model ARF.     

关白附多糖体外抗氧化性研究

利用水提分级醇沉法从关白附中提取可溶性多糖,采用邻苯三酚自氧化、Fenton体系和H2O2致鼠肝脏脂质过氧化的方法,观察体外加入关白附多糖对这些氧化反应的影响。研究结果表明:关白附多糖对.O2-抑制作用较好,最大抑制率为51.80%;对.OH抑制作用显著,最大抑制率为90.88%;对肝脂质过氧化的抑制率可达100%。     

Effect of prolonged whole-body hyperthermia on adult male rat testes and the protective role of vitamin C and E: A histological and biochemical study

Hyperthermia (HT) is a significant risk factor for male infertility. Most researchers investigated the effect of localized and short-term HT on male fertility. This study aimed to assess the harmful impacts of prolonged and generalized HT on testicular histology and ultrastructure in rats. The possible protective effects of vitamin E (Vit E), Vit C, and their combination were also investigated. Thirty male adult Wister rats were used (5 groups). 1- control, 2- HT, 3- Vit C, 4- Vit E, and 5- Vit C + Vit E. Rats in groups 2–5 were subjected to HT (41°C), 1 hr daily for 2 weeks. HT-induced a significant decrease in body weight gain, food and water intake, and serum testosterone. HT showed a damaging effect on the testicular and coda epididymis tissue. HT significantly (p ≤ .05) produced oxidative stress (decreased serum catalase (145.49 ± 8.98), glutathione peroxidase (20.27 ± 4.46), superoxide dismutase (2.68 ± 0.54), and reduced glutathione (5.18 ± 0.33), and increased malondialdehyde (9.46 ± 1.55). Vit E alone and combined with Vit C, significantly protected the gonads against the deleterious effects of HT. The results recommended that prolonged HT of the whole body is harmful to male fertility. Prophylactic therapy with Vit E could help decrease the HT-induced male gonadal harm.     

Cardioprotective Effect of Succinate Against Ischemia/Reperfusion Injury

(Received for publication on Sept. 12, 1996; accepted on May 12, 1997)     

乌司他丁对下肢缺血-再灌注损伤的影响

目的观察乌司他丁对下肢缺血-再灌注期间氧自由基(OFR)代谢物丙二醛(MDA)以及促炎性细胞因子肿瘤坏死因子α(TNF-α)的影响。方法将20例单侧下肢手术病人随机分为乌司他丁组(U组,n=10)和对照组(C组,n=10)。均采用连续硬膜外麻醉。U组于上止血带前15min静脉滴注乌司他丁20万单位,松止血带前5min再次推注10万单位;C组以等量生理盐水于相同时间静脉注射。于上止血带前(T1)、松止血带后5min(T2)、15min(T3)和30min(T4)抽取术侧股静脉血,测定MDA、TNF-α浓度。结果C组在T2、T3、T4时MDA含量较T1时显著增加(P<0·01),U组仅T4时较T1时增加(P<0·05)。C组TNF-α于T3、T4时较T1时显著增高(P<0·01),U组各时点较T1时差异无显著性。结论乌司他丁对下肢缺血-再灌注损伤中OFR代谢物MDA以及促炎性细胞因子TNF-α的产生有一定抑制作用。     

The role of oxygen-derived free radicals and the effect of free radical scavengers on skeletal muscle ischemia/reperfusion injury

The aim of this study was to clarify the role of oxygen-derived free radicals and the effect of free radical scavengers on skeletal muscle ischemia/reperfusion injury. Male Wistar rats were divided into a complete ischemia group (C-group) and an incomplete ischemia group (IC-group) and each animal was subjected to 2h of ischemia and 1h of reperfusion. In an attempt to decrease reperfusion injury, the rats were given free radical scavengers either as allopurinol 50 mg/kg for 2 days or as superoxide dismutase 60,000 units/kg plus catalase 500,000 units/kg. Tissue malondialdehyde, a product of lipid peroxidation, was measured as an indicator of free radicals, with higher levels indicating higher concentrations of free radicals. The malondialdehyde level in the gastrocnemius muscle after 1h of reperfusion increased significantly in both groups when compared to the levels before and 2h after ischemia, although there was no significant difference between the two groups. The water content of the gastrocnemius muscle and serum creatinine phosphokinase MM isoenzyme (CPK-MM) in both groups, and GOT in the C-group, increased significantly after 1h of reperfusion when compared the values before and 2h after ischemia. In the C-group, these values were significantly higher than in the IC-group. The administration of free radical scavengers suppressed the increase in malondialdehyde in the gastrocnemius muscle after reperfusion in both groups. The increase in water content and CPK-MM after reperfusion was also suppressed by free radical scavengers in the IC-group, but not in the C-group. These findings suggest that ischemic damage predominates in complete severe ischemia/reperfusion injury, whereas reperfusion injury predominates in incomplete mild ischemia/reperfusion injury.     

Study of the protective effect of vitamin C on testicular tissue following experimental unilateral cryptorchidism in rats

This study investigated the role of vitamin C as an antioxidant in protecting the testis against damage in experimental unilateral cryptorchidism. Forty‐five male Wistar Albino rats were divided into three groups. The control group had intact rats, the cryptorchid group had unilateral cryptorchid rats and the treatment group had unilateral cryptorchid rats that it received vitamin C at a dose of 50 mg kg^?1 body weight intraperitoneal, once a day, during experimental period. Histopathological samples were obtained from five cases of 15 animals of each group at 15, 30 and 60 days after induction of cryptorchidism. The results showed histopathological parameters of the cryptorchid (left) testes in the cryptorchid group significantly decreased compared with the control group (P < 0.05), and treatment with vitamin C after 60 days significantly improved all parameters of these testes compared with the cryptorchid group (P < 0.05). In addition, the left testes on unilateral cryptorchid rats had noticeable adverse effects on the scrotal (right) testes (P < 0.05). Treatment with vitamin C after 60 days significantly improved all parameters of these testes compared with the cryptorchid group (P < 0.05). It can be concluded that treatment with vitamin C significantly improved histopathological parameters in scrotal testes on unilateral cryptorchid rats.