The Protective Role of Glutathione, Cysteine and Vitamin C against Oxidative DNA Damage Induced in Rat Kidney by Potassium Bromate

The roles of glutathione (GSH), cysteine, vitamin C., liposome-encapsulated superoxide dismutase (L-SOD) and vitamin E in preventing oxidative DNA damage and cytotoxicity in the rat kidney after administration of potassium bromate (KBrO₃) to male F344 rats were investigated by measuring 8-hydroxydeoxyguanosine (8-OH-dG), an oxidative DNA product, lipid peroxidation (LPO) levels and relative kidney weight (RKW). Combined pre- and posttreatment of animals with 2 × 800 mg/kg GSH i.p. inhibited the increase of 8-OH-dG, LPO levels and RKW caused by 80 mg/kg KBrO₃ i.p. administration. In contrast, pretreatment with 0.3 ml/kg diethylmaleate (DEM) i.p., a depletor of tissue GSH, was associated with elevation of 8-OH-dG, LPO levels and RKW after a 20 mg/kg KBrO₃ i.p. treatment, which itself caused no change. Administration of KBrO₃ itself reduced renal non-protein thiol levels, but this was inhibited by the two doses of exogenous GSH. Combined treatment with DEM and KBrO₃ lowered the non-protein thiol level in the kidney more than did DEM treatment alone. Protective effects against the oxidative damage caused by KBrO₃ were also observed for pre- and posttreatment with 400 mg/kg cysteine i.p., another sulfhydryl compound, and daily i.g. application of 200 mg/kg vitamin C for 5 days. However, no influence was evident after pre- and posttreatment with 18,000 U/kg L-SOD i.p. or daily i.g. 100 mg/kg of vitamin E for 5 days. The results suggest that intracellular GSH plays an essential protective role against renal oxidative DNA damage and nephrotoxicity caused by KBrO₃.     

Spectroelectrochemical studies of tetrasulfonated metallophthalocyanines adsorbed on the basal plane of graphite in the presence of cysteine

Cobalt and iron tetrasulfonated phthalocyanines (M-TSPc) have been studied by electroreflectance spectroscopy in the adsorbed state on the basal plane of HOPG in a borate buffer (pH 9). Since both complexes exhibit electrocatalytic activity for the electro-oxidation of cysteine, we looked at the changes of the visible spectra of the adsorbed complexes upon adding millimolar amounts of cysteine to the electrolyte. Under zero-current conditions (open circuit) the addition of cysteine causes large changes in the reflectance spectra of both Co-TSPc and Fe-TSPc. In the case of Co-TSPc the spectra resemble that of Co(I)TSPc whereas for Fe-TSPc bands at 424 and 626 nm are observed. The open circuit potential shifts to values close to the standard potential of the M(II)/M(I) couple. We attribute these changes, particularly in the case of Fe-TSPc, to the formation of a radical adduct between the adsorbed phthalocyanine and the cysteine molecule, with partial electron-transfer from the cysteine to the metal center. Evidences for these adducts is not found when polarizing the electrode, which shows that they behave as very unstable intermediates in the catalytic process.     

Low plasma glutamine in combination with high glutamate levels indicate risk for loss of body cell mass in healthy individuals: the effect of N-acetyl-cysteine

Skeletal muscle catabolism, low plasma glutamine, and high venous glutamate levels are common among patients with cancer or human immunodeficiency virus infection. In addition, a high glycolytic activity is commonly found in muscle tissue of cachectic cancer patients, suggesting insufficient mitochondrial energy metabolism. We therefore investigated (a) whether an anaerobic physical exercise program causes similar changes in plasma amino acid levels, and (b) whether low plasma glutamine or high glutamate levels are risk factors for loss of body cell mass (BCM) in healthy human subjects, i.e., in the absence of a tumor or virus infection. Longitudinal measurements from healthy subjects over longer periods suggest that the age-related loss of BCM occur mainly during episodes with high venous glutamate levels, indicative of decreased muscular transport activity for glutamate. A significant increase in venous glutamate levels from 25 to about 40 M was seen after a program of anaerobic physical exercise. This was associated with changes in T lymphocyte numbers. Under these conditions persons with low baseline levels of plasma glutamine, arginine, and cystine levels also showed a loss of BCM. This loss of BCM was correlated not only with the amino acid levels at baseline examination, but also with an increase in plasma glutamine, arginine, and cystine levels during the observation period, suggesting that a loss of BCM in healthy individuals terminates itself by adjusting these amino acids to higher levels that stabilize BCM. To test a possible regulatory role of cysteine in this context we determined the effect of N-acetyl-cysteine on BCM in a group of subjects with relatively low glutamine levels. The placebo group of this study showed a loss of BCM and an increase in body fat, suggesting that body protein had been converted into other forms of chemical energy. The decrease in mean BCM/body fat ratios was prevented by N-acetyl-cysteine, indicating that cysteine indeed plays a regulatory role in the physiological control of BCM.Abbreviations BCM Body cell mass - HIV Human immunodeficiency virus type 1 - NAC N-Acetyl-cysteine     

Skin deposits in hereditary cystatin C amyloidosis

Summary Clinically normal skin from 47 individuals aged 9–70 years was investigated. Cystatin C amyloid deposits were found in various locations of the skin by light and/or electron microscopy, in all 12 patients with a clinical history of hereditary cystatin C amyloidosis (HCCA). Six asymptomatic individuals, who had the Alu 1 restriction fragment length polymorphism (RFLP) marker reported to cosegregate with the disease, also had cystatin C amyloid deposits in the skin. Three asymptomatic individuals (age 17–46) belonging to the HCCA families were without amyloid in the skin but had Alu 1 RFLP marker. Skin from 12 individuals who served as controls and skin from 14 close relatives of the patients was negative for amyloid. Punch biopsy of the skin is a simple procedure which is of value for the diagnosis of HCCA, even before the appearance of clinical symptoms. This method might also be of use in following progression of the disease.     

Acute renal dysfunction by cadmium injected with cysteine in relation to renal critical concentration of cadmium

In order to study the critical concentration of cadmium (Cd) in acute renal dysfunction following Cd, male mice were injected IV with Cd complexed with cysteine. The critical concentration was 10 g Cd/g wet weight in whole kidney and it was the same as that for Cdthionein (Cd-Th), which may suggest that the toxicity of Cd-Th is due to Cd ions liberated from Cd-Th in the kidneys. Renal Cd concentration was at first higher than the critical concentration, but decreased to the critical concentration by 24 h after administration. As an index for renal dysfunction, the uptake of p-aminohippurate (PAH) by renal cortical slices in vitro was sensitive, and showed the different time-course from those of urinary protein and glucose levels. The results suggest the usefulness of PAH uptake as an index. Incidental to the renal dysfunction, renal calcium levels exhibited a marked increase.     

叶酸和辛伐他汀对高同型半胱氨酸血症引起的大鼠动脉粥样硬化疗效对比

目的探讨叶酸及辛伐他汀对高同型半胱氨酸血症(HHcy)引起的大鼠动脉粥样硬化(AS)治疗效果的差异。方法将36只健康8周龄SD雄性大鼠随机分为健康对照组、高蛋氨酸饮食组、叶酸治疗组和辛伐他汀治疗组。12周后,采用高效液相色谱法检测血浆同型半胱氨酸(Hcy)浓度;采用酶法检测血脂浓度;通过光镜和电镜观察胸主动脉形态学变化;采用免疫组织化学方法检测胸主动脉平滑肌细胞中依赖正常T细胞激活表达和分泌的因子(RANTES)、趋化因子受体-1(CCR-1)蛋白的表达;采用反转录-聚合酶链反应(RT-PCR)方法检测胸主动脉平滑肌细胞RANTES、CCR1 mRNA的表达。结果高蛋氨酸饮食组血浆Hcy浓度明显高于其余3组;叶酸治疗组血浆Hcy浓度明显低于辛伐他汀治疗组(P<0.05)。各组大鼠血浆总胆固醇与甘油三酯浓度差异无统计学意义(P>0.05)。光镜和电镜下可见健康对照组大鼠胸主动脉壁基本结构正常,高蛋氨酸饮食组大鼠胸主动脉呈AS早期改变,治疗组大鼠动脉病变较轻。免疫组织化学结果显示,RANTES和CCR-1蛋白在高蛋氨酸饮食组主动脉平滑肌细胞中表达的平均灰度值显著低于其余3组。且在叶酸治疗组表达的平均灰度显著低于辛伐他汀治疗组(P<0.05)。RT-PCR结果亦表明RANTES和CCR-1 mRNA均在高蛋氨酸饮食组主动脉平滑肌细胞中的表达最高。且在叶酸治疗组的表达均显著高于辛伐他汀治疗组(P<0.05)。结论高蛋氨酸饮食能引起大鼠HHcy形成,促进主动脉平滑肌细胞中RANTES及受体CCR-1的表达,进而诱导AS发生,此过程与血脂无关。辛伐他汀及叶酸均可降低血浆Hcy浓度、抑制动脉壁平滑肌细胞中RANTES及CCR-1的表达,减轻Hcy对动脉壁的损伤,防止AS的发生,但以叶酸降低血浆Hcy的作用更强,辛伐他汀对RANTES和CCR-1表达的抑制作用更明显。     

甲钴胺对脑缺血-再灌注大鼠皮层神经细胞凋亡的预防作用

目的 探讨甲钴胺对缺血-再灌注(I-R )大鼠大脑皮层神经细胞凋亡的影响.方法Wistar大鼠135只随机均分为五组 :A组为空白对照 ;B、C、D和 E组分别用0.9% 氯化钠20 ml · kg-1 ·d-1 、尼莫地平1mg·kg-1 ·d-1 、甲钴胺50μg·kg-1 ·d-1和100μg·kg-1 ·d-1灌胃1周后建立脑I-R模型.观察再灌注24 h后神经功能缺损评分.再灌注6、12和24 h ,用T U N EL法检测大脑皮层细胞凋亡 ,Western blot检测大脑皮层半胱氨酸天冬氨酸酶3(Caspase-3)蛋白表达.结果 再灌注24 h后 ,C、E组神经功能评分低于B、D组( P＜0 .05或P＜0 .01 ).C、D和E组神经细胞凋亡数均少于B组 ,E组少于D组(P＜0 .01).C、D和E组大脑皮层Caspase-3表达均低于B组 ,D组高于C组(P＜0 .01).结论 预用甲钴胺对大鼠脑I-R损伤有保护作用 ,可能与抑制大脑组织Caspase-3蛋白表达有关.     

α-硫辛酸对高糖 高同型半胱氨酸诱导的小鼠足细胞凋亡的影响

目的探讨α-硫辛酸对高糖、高同型半胱氨酸(Hcy)作用下小鼠足细胞凋亡及Nephrin mRNA表达的影响。方法将体外培养的足细胞用高糖(25mmol/L)、Hcy(1mmol/L)、α-硫辛酸(0.5mmol/L)干预,分别在干预24、48、72h时收集细胞,流式细胞仪检测细胞凋亡,反转录聚合酶链反应(RT-PCR)法检测Nephrin mRNA表达。结果 24h时,高糖组、高Hcy组及混合组未见明显细胞凋亡(P>0.05);48h时,上述3组可见明显的细胞凋亡,且混合组凋亡更加明显(P<0.01);72h时,上述差异更加明显(P<0.01);α-硫辛酸可对抗高糖、高Hcy引起的足细胞凋亡(均P<0.05),且有一定的时间依赖性;高糖、高Hcy环境下,足细胞Nephrin mRNA表达呈下降趋势,且有一定的时效性;α-硫辛酸可对抗上述趋势。结论α-硫辛酸可减弱高糖、高Hcy对足细胞促凋亡作用,还可对抗其下调Nephrin mRNA的表达。     

血清半胱氨酸蛋白酶抑制剂C、β2微球蛋白及肾血流动力学对过敏性紫癜早期肾损害的诊断价值

目的探讨过敏性紫癜（HSP）患儿血清半胱氨酸蛋白酶抑制剂C（cystatin．C）、β2微球蛋白（β2-MG）及肾血流动力学变化对早期肾损害的临床意义。方法选取46例HSP患）L（HSP组）和40例健康儿童（对照组）。运用ELISA法测定血清cystatin-C,放射免疫法测定血清β2-MG,彩色多普勒超声检测肾血流动力学变化。结果HSP组患儿血清eystatin．C[（3．96±1．52）msm]及β2-MG[（2．74±0．82）ms／L]均显著高于对照组[（1．67±0．61）mg／L和（1．89±0．47）mg／L],P值均〈0．01。HSP组患儿肾血流频谱为高速高阻型,肾主动脉收缩期最大峰值流速[（1．068±0．348）m／s]和阻力指数（0．894±0．125）均高于对照组[（0．859±0．357）m／s和0．726±0．078],P值均〈0．05。结论联合检测血清cystatin-C及肾血流动力学变化能大大提高早期发现肾损害的敏感性。     

湛江市健康人群血清半胱氨酸蛋白酶抑制剂C浓度的调查及参考值范围的建立

目的：调查本市健康人群血清半胱氨酸蛋白酶抑制剂C（Cys C）的浓度分布及建立相应的参考值范围。方法：采用免疫透射比浊法检测2529名健康人群血清Cys C含量。结果：健康人群血清Cysc参考值范围：男性为0．62～1．05mg／L,平均为0．84±0．08mg／L;女性为O．53～0．99mg/L。平均为0．76±0．09mg／L。同性别不同年龄组之间血清CysC浓度差异无统计学意义（P〉0．05）：1～60岁年龄段,男女性别之间血清CysC浓度差异有统计学意义（P〈0．05）。结论：建立了本市6个月以上健康人群血清CysC参考值范围,为相关疾病的诊断及疗效观测提供相应参数。