多普勒超声评价维生素C和维生素E对高血压血管内皮舒张功能的影响

目的应用超声技术观察维生素C,维生素E对高血压患者肱动脉内皮依赖性舒张功能的影响。方法研究对象包括20例高血压患者和20例正常人分别服用维生素C、维生素E12个月前后,应用高分辩力超声测定静息状态下,反应性充血后,舌下含服硝酸甘油后的肱动脉内径,并计算反应性充血和硝酸甘油诱发的内径百分变化率。结果反应性充血前后肱动脉内径百分变化率,高血压组明显低于正常组(P<0.001),硝酸甘油诱发的肱动脉内径百分变化率高血压组和正常组无显著差异。服用维生素C、维生素E12个月后,高血压患者反应性充血前后肱动脉内径百分变化率明显高于治疗前(P<0.001)。但硝酸甘油诱发的肱动脉内径百分变化率无明显变化。结论服用维生素C、维生素E可改善高血压患者受损的内皮依赖性血管舒张功能。     

Neonatal Bladder Inflammation Produces Functional Changes and Alters Neuropeptide Content in Bladders of Adult Female Rats

Neonatal bladder inflammation has been demonstrated to produce hypersensitivity to bladder re-inflammation as an adult. The purpose of this study was to investigate the effects of neonatal urinary bladder inflammation on adult bladder function and structure. Female Sprague-Dawley rats were treated on postnatal days 14 to 16 with intravesical zymosan or anesthesia alone. At 12 to 16 weeks of age, micturition frequency and cystometrograms were measured. Similarly treated rats had their bladders removed for measurement of plasma extravasation after intravesical mustard oil, for neuropeptide analysis (calcitonin gene-related peptide or Substance P) or for detailed histological examination. Rats treated with zymosan as neonates exhibited increased micturition frequency, reduced micturition volume thresholds, greater extravasation of Evans blue after intravesical mustard oil administration, and greater total bladder content of calcitonin gene-related peptide and Substance P. In contrast, there were no quantitative histological changes in the thickness, fibrosis, or mast cells of bladder tissue due to neonatal zymosan treatments. Functional changes in urologic systems observed in adulthood, coupled with the increased neuropeptide content and neurogenic plasma extravasation in adult bladders, suggest that the neonatal bladder inflammation treatment enhanced the number, function, and/or neurochemical content of primary afferent neurons. These data support the hypothesis that insults to the urologic system in infancy may contribute to the development of adult bladder hypersensitivity.PerspectiveInflammation of the bladder early in life in the rat has multiple sequelae, including laboratory measures that suggest an alteration of the neurophysiological substrates related to the bladder. Some painful bladder syndromes in humans have similar characteristics and so may be due to similar mechanisms.     

临沂市区学龄前儿童血铅和血镉水平调查研究

目的了解临沂市区学龄前儿童血铅和血镉水平及铅、镉超标状况。方法在严格质量控制下,应用高灵敏度原子吸收光谱法对临沂市区1228名学龄前儿童进行血铅和血镉含量检测并统计分析。结果122名学龄前儿童血铅和血镉水平均值分别为75.8ug/L和2.33ug/L。其中,血铅含量≥100ug/L者210例,铅中毒率为17.10%;血镉>5ug/L者14例,超标率为1.14%。不同性别间学龄前儿童血铅水平均值和铅中毒率差异均无显著性(P>0.05);而血镉均值和超标率差异均有显著性(P<0.05)。结论临沂市区学龄前儿童血铅和血镉水平均较高,铅和镉超标状况不容乐观,应引起儿童家长乃至全社会的高度重视。     

Endocardial Pacemakers in Children: Lead Length and Allowance for Growth

Permanent endocardial pacing in small children is feasible but is limited by two problems; sufficient extra lead has to be left within the heart to allow for growth and the excess has to be coiled behind the pacemaker, limiting the benefit from smailer generators. The required intravascuiar lead length in 120 children and aduits was measured on posteroanterior chest X ray and was correlated with standing height. Measurements were made from the mid-point of the left ciavicle to the apex of the right ventricle in a curve simulating the usual endocardial lead position. In 60 children, aged 2.0–15.9 years, intravascular lead length (range 15.5–29.0 cm) correlated well with height (0.83–1.70 m), r = 0.91. in 60 adults, mean age 54.9 years, intravascular lead length (25.5–35.6 cm) also correlated well with height (1.45–1.85 m), r = 0.71. In 20 adults the excess extravascuiar lead length, measured during pacemaker impiantation via the subclavian route, was 15.1–33.7 cm and was inversely correlated with height. A child's eventual adult height can be predicted and, using our data, the extra length of lead necessary to allow for growth can be computed. Available endocardial pacing leads are usually 58- to 64-cm long. The excess extravascular lead is a major practical difficulty in children. Shorter leads would avoid the problem of excess lead and facilitate long-term pacing in small children.     

Vitamin C in the critically ill - indications and controversies

Ascorbic acid (vitamin C) elicits pleiotropic effects in the body. Among its functions, it serves as a potent anti-oxidant, a co-factor in collagen and catecholamine synthesis, and a modulator of immune cell biology. Furthermore, an increasing body of evidence suggests that high-dose vitamin C administration improves hemodynamics, end-organ function, and may improve survival in critically ill patients. This article reviews studies that evaluate vitamin C in pre-clinical models and clinical trials with respect to its therapeutic potential.     

Experimental Studies on the Effect of Chlorpyriphos and Lead Acetate on Biochemical Parameters in Wistar Rats with Special Reference to Ameliorative Effect of Vitamin C

The present study was designed to evaluate the effects of chlorpyriphos, lead acetate, vitamin c alone, and in combination on various biochemical parameters in wistar rats. Rats of 150–200 g body weight were divided into eight groups of six animals each and were subjected to various daily oral treatment regimes for 98 days. Group I served as control receiving only corn oil, group II received chlorpyriphos at 5.5 mg/kg in corn oil, group III received lead acetate at 100 ppm in water, whereas animals in group IVth received a combination of chlorpyriphos at 5.5 mg/kg in corn oil and lead acetate at 100 ppm in water. Group Vth received vitamin C at 100 mg/kg in water, group VIth received a combination of chlorpyriphos at 5.5 mg/kg and vitamin C at 100 mg/kg, group VIIth received lead acetate at 100 ppm in water and vitamin C at 100 mg/kg and group VIIIth received chlorpyriphos at 5.5 mg/kg, lead acetate at 100 ppm in water and vitamin C at 100 mg/kg. Chlorpyriphos and lead acetate alone or in combination elevated the activities of plasma aminotransferases, phosphatases, creatinine and blood urea nitrogen where as decreased the total plasma protein levels both due to chlorpyriphos and lead acetate treatment alone or in combination. The results showed that alterations in the biochemical parameters induced by co-exposure to chlorpyriphos and lead were mitigated by pretreatment with vitamin C. It is recommended that further research be geared towards identifying more agents that may ameliorate such adverse effects.     

Dietary patterns and A1C in Japanese men and women

OBJECTIVE—Dietary patterns in Western populations have been linked to type 2 diabetes, but the role of diet in Japanese remains unclear. We investigated the association between major dietary patterns and glucose tolerance status as measured by A1C in Japanese adults.RESEARCH DESIGN AND METHODS—The groups of subjects were comprised of 3,243 men and 4,667 women who participated in the baseline survey of an ongoing cohort study on lifestyle-related diseases in Fukuoka, Japan. Dietary patterns were derived by using principal-component analysis of the consumption of 49 food items, ascertained by a food-frequency questionnaire. Logistic regression analysis was used to estimate sex-specific odds ratios (ORs) of elevated A1C (≥5.5%), with adjustment for potential confounding variables.RESULTS—The Westernized breakfast pattern characterized by frequent intake of bread but infrequent intake of rice was inversely related to A1C concentrations (P_trend = 0.02 in both men and women); the multivariate-adjusted ORs for the highest versus lowest quintiles were 0.60 (95% CI 0.43–0.84) and 0.64 (0.46–0.90) for men and women, respectively. The seafood dietary pattern was positively associated with A1C concentrations in men only (P_trend = 0.01). Neither the healthy nor high-fat dietary pattern was related to A1C.CONCLUSIONS—A dietary pattern featuring frequent intake of white rice may deteriorate glucose metabolism in Japanese men and women, and the salty seafood dietary pattern may have a similar effect in men.The prevalence of type 2 diabetes is increasing worldwide (1). Likewise, the Japanese, who have experienced rapid economic growth during the past several decades, now have a high prevalence of type 2 diabetes (2). However, this situation seems peculiar given that obesity, a strong determinant of the disease (3), is much less common among Japanese than among Western populations (4,5). It has been postulated that the Japanese are predisposed to type 2 diabetes because of their low levels of insulin secretion and sensitivity, which may be determined by both genetic and environmental factors (4,5). The investigation of a Japanese diet in relation to type 2 diabetes may provide a clue to the issue.The relation of specific foods and nutrients such as vegetables (6), dietary fiber (7), and glycemic load (8) to risk of type 2 diabetes has been examined in many studies, but few have addressed the association with dietary patterns. Although the effect of a single nutrient, food, or food group on disease risk and morbid conditions has often been investigated, such an effect is difficult to assess in observational studies because foods and nutrients are consumed in combination, and their complex effects are likely to be interactive or synergistic (9). To overcome problems relating to the close intercorrelation among foods or nutrients, analysis of dietary patterns has gained much interest. A dietary pattern is a comprehensive variable that integrates consumption of several foods or food groups and is expected to have a greater impact on disease risk than any single nutrient (9). Studies in Western populations have suggested that risk of type 2 diabetes is associated inversely with prudent or healthy dietary patterns (10–12) and positively with a Western dietary pattern (11–14). To the best of our knowledge, however, only one study reported an association between a Japanese dietary pattern and type 2 diabetes (15). The aim of the present study was, therefore, to investigate dietary patterns in relation to glucose tolerance status as measured by A1C concentrations in Japanese adults.     

超声评价维生素C和维生素E对糖尿病血管内皮舒张功能的影响

目的超声观察维生素C、维生素E对2型糖尿病患者肱动脉内皮依赖性舒张功能的影响.方法 46例糖尿病患者随机分为维生素C、维生素E治疗组(A组)和对照组 (B组),采用高分辨率超声观察治疗前后血流介导的肱动脉内皮依赖性血管舒张和硝酸甘油介导的非内皮依赖性血管舒张.结果服用维生素C、维生素E 12个月后,A组血流介导的血管扩张明显改善[(6.33±1.89)%对(4.4±2.67)%,P＜0.01],B组无变化[(4.53±1.99 )%对(4.62±2.47)%,P＞0.05];硝酸甘油介导的血管扩张两组均较治疗前无显著差异性[分别为(20.67±3.29)%对(19.68±2.26)%,(19.45±3.03)%对(20.38 ±1.82)%,P＞0.05];A组24 h尿蛋白排泄率较治疗前减低[(121.87±104.47) mg/24 h对(238.52±231.26) mg/24 h,P＜0.05],B组无明显变化[(211.78±2 08.07) mg/24 h 对(209.78±210.04) mg/24 h,P＞0.05].结论服用维生素C、维生素E可改善糖尿病患者受损的内皮依赖性血管舒张功能,并对肾脏具有一定的保护作用.     

Effect of Different Levels of Dietary Vitamin C on Growth Performance,Muscle Composition,Antioxidant and Enzyme Activity of <Emphasis Type="Italic">Macrobrachium rosenbergii</Emphasis>

A 12- week feeding trial was conducted to determine the effects of dietary vitamin C levels on the growth performance, antioxidant ability, muscle composition and enzyme activity in freshwater prawn, Macrobrachium rosenbergii. The experimental basal diets were supplemented with M. rosenbergii at the rates of 0 (control), 25, 50, 75, 150 and 300 mg/kg dry feed weight and the assays were in triplicate. Growth performance, body composition, antioxidant activity and serum biochemistry parameters were determined. However, the present investigation revealed that prawns fed with diet supplemented with 25–150 mg/kg of vitamins C shows enhanced (P < 0.05) growth performance, including final weight and weight gain. Additionally, prawns fed with 25–150 mg/kg of vitamins C supplemented diets achieved significant (P < 0.05) improvement in growth performance, digestive enzyme activities, and muscle biochemical composition, while, the prawns fed with 150 mg/kg of vitamin C showed enhanced performance respectively. However, the prawns fed with above 150–300 mg/kg showed poor performance. The antioxidant enzymatic activity (SOD, CAT) metabolic enzyme status in muscle showed no significant (P > 0.05) alterations in prawns fed with 25–150 mg/kg of vitamin C supplemented diets. Therefore, the present findings suggested that 150 mg/kg of vitamin C could be supplemented for flexible enhanced survival, growth, antioxidant defense system and production of M. rosenbergii.     

Vitamin C supplementation in the patient with burns and renal failure.

Vitamin C supplementation is an important component of nutritional management in patients with burns. To supply appropriate vitamin C therapy, complications such as renal failure must be considered. An understanding of current vitamin regimens and potential metabolic sequelae can assist the practitioner in providing safe and therapeutic vitamin C doses.     

Intakes of Dietary Fiber,Vegetables, and Fruits and Incidence of Cardiovascular Disease in Japanese Patients With Type 2 Diabetes

OBJECTIVE

Foods rich in fiber, such as vegetables and fruits, prevent cardiovascular disease (CVD) among healthy adults, but such data in patients with diabetes are sparse. We investigated this association in a cohort with type 2 diabetes aged 40–70 years whose HbA_1c values were ≥ 6.5% in Japan Diabetes Society values.

RESEARCH DESIGN AND METHODS

In this cohort study, 1,414 patients were analyzed after exclusion of patients with history of CVDs and nonresponders to a dietary survey. Primary outcomes were times to stroke and coronary heart disease (CHD). Hazard ratios (HRs) of dietary intake were estimated by Cox regression adjusted for systolic blood pressure, lipids, energy intake, and other confounders.

RESULTS

Mean daily dietary fiber in quartiles ranged from 8.7 to 21.8 g, and mean energy intake ranged from 1,442.3 to 2,058.9 kcal. Mean daily intake of vegetables and fruits in quartiles ranged from 228.7 to 721.4 g. During the follow-up of a median of 8.1 years, 68 strokes and 96 CHDs were observed. HRs for stroke in the fourth quartile vs. the first quartile were 0.39 (95% CI 0.12–1.29, P = 0.12) for dietary fiber and 0.35 (0.13–0.96, P = 0.04) for vegetables and fruits. There were no significant associations with CHD. The HR per 1-g increase was smaller for soluble dietary fiber (0.48 [95% CI 0.30–0.79], P < 0.01) than for total (0.82 [0.73–0.93], P < 0.01) and insoluble (0.79 [0.68–0.93], P < 0.01) dietary fiber.

CONCLUSIONS

Increased dietary fiber, particularly soluble fiber, and vegetables and fruits were associated with lower incident stroke but not CHD in patients with type 2 diabetes.Type 2 diabetes is a significant cause of premature mortality and morbidity related to cardiovascular disease (CVD), and medical nutritional therapy is an essential component of diabetes care aimed toward prevention of CVD. Current guidelines for diabetes care in many countries encourage consumption of dietary fiber, nondigestible carbohydrates, and lignin that are intrinsic and intact in plants, setting a variety of goals for daily intake of total dietary fiber (14 g/1,000 kcal in the U.S. [1], 40 g in Europe [2], 25–50 g in Canada [3], and 20–25 g in Japan [4]). An increase in dietary fiber can reduce CVD risk through a variety of mechanisms, such as decreasing total and LDL cholesterol (5), reducing postprandial glucose concentration and insulin secretion (6), lowering blood pressure (7), reducing clotting factors (8), and reducing inflammation (9). Lipid-lowering effects were attributable to soluble fiber (5), which reduces absorption of fat and binds bile acids (10). The effects of an unfortified high-fiber (50 g per day) diet on glycemic control and lipids were also demonstrated in a randomized trial in patients with type 2 diabetes (11).Cohort studies of healthy adults suggest that foods rich in fiber protect against coronary heart disease (CHD) (12) and stroke (Supplementary Table 1) (13–19), but data on patients with type 2 diabetes are sparse (20–22) despite the integral role of medical nutritional therapy. All of the earlier studies in diabetes were conducted in the U.S. and Europe, and the effects of dietary fiber on CVD remain unknown for Asian patients, who account for >60% of the diabetic population worldwide (23). In comparison with type 2 diabetic patients in Western countries, those in East Asian countries, including Japan, are known to have different features regarding cardiovascular complications (24) including a much lower incidence rate of CHD than in Western countries (25) and obesity as a lesser cardiovascular risk factor (20). Therefore, it is still uncertain whether dietary recommendations established by the earlier studies are universally applicable to patients with type 2 diabetes, particularly to Japanese patients. This study therefore aimed to investigate the incidence rates of stroke and CHD in relation to intake of dietary fiber in total, soluble form, and insoluble form and vegetables and fruits in a cohort of Japanese patients with type 2 diabetes.     

维生素C对人体疾病的影响及其在康复预防中的作用

维生素C作为人体中不可缺少的维生素之一,与人体的健康有着密切的关系。适当的在不同年龄段补充适量的维生素C对许多疾病都有预防作用,而许多疾病的发生可能或多或少与维生素C的缺乏有关系,另外维生素C还能和许多其他药物联合用药治疗某些疾病。所以在日常生活中注意不挑食,不偏食,多食绿色蔬菜和水果,适时适量补充维生素C是有必要的。     

Vitamin C modifies the cardiovascular and microvascular responses to cigarette smoke inhalation in man

Both neutrophil margination and increases in the non-invasively assessed parameter, isovolumetric venous congestion cuff pressure (Pv(i)), are symptomatic of some inflammatory diseases. Neutrophil margination occurs primarily, though not exclusively, at the post-capillary endothelial surface. The local haemodynamic changes resulting from margination may be responsible for the observed increases in Pv(i). Smoke inhalation has been shown in animal studies to cause an increase in post-capillary neutrophil margination by mechanisms that can be blocked by oral vitamin C administration. We looked for indices of a relationship between margination and Pv(i) in man, using cigarette smoke inhalation as a pathophysiological challenge. We also examined the effect of prophylactic vitamin C on the response. Smoke inhalation was associated with highly significant increases in both Pv(i) and heart rate. After vitamin C pre-treatment, no increase in Pv(i) was observed in response to the smoke inhalation; however, whilst heart rate still increased significantly, the duration of this response was attenuated. The results suggest that vitamin C affords protection against some of the cardiovascular and microvascular changes associated with cigarette smoke inhalation in man. They also support the notion that non-invasive assessment of changes in Pv(i) may provide a measurable index of systemic changes in inflammatory conditions.     

基质金属蛋白酶-9和维生素D受体与高血压肾损害的相关性研究

目的　了解高血压肾损害患者血清基质金属蛋白酶 - 9( MMP- 9)浓度、2 5 OH Vit D及维生素 D受体 ( VDR)含量。探讨基质金属蛋白酶 - 9和维生素 D受体在高血压肾损害发病中所起的作用。方法　观察对象为收缩压 ( SBP) >40 mm Hg,舒张压 ( DBP) >90 mm Hg;BUN>2 0 mmol/L,Scr>445 μmol/L,Ccr<2 0 ml/min的高血压肾损害患者共 44例 ;正常对照组 2 8例 ,用 ELISA法和细胞提取和裂解的方法测定两组之间血清基质金属蛋白酶 - 9浓度、2 5 OH Vit D和维生素 D受体含量 ,并探讨 2 5 OH Vit D及维生素 D受体与肾损害蛋白尿的关系。结果　血清 MMP- 9在高血压肾损害组高于正常对照组 ( 72 3.5± 1 90 .7VS,41 8.2± 1 65 .0 ,P<0 .0 1 ) ,血清 2 5 OH Vit D、血淋巴细胞 VDR含量低于正常对照组 ( 90 .79± 6.5 3VS,5 8.2 1± 9.5 0 ,P<0 .0 1 )和 ( 2 0 .31± 4.76VS,1 3.5 0± 2 .5 5 ,P<0 .0 1 )。2 5 OH Vit D、VDR与蛋白尿呈显著负相关。结论　 MMP- 9可能参与了高血压肾损害的发生发展过程 ,高血压肾损害则导致血清 2 5 OHVit D、血淋巴细胞 VDR含量下降     

Contralateral High or a Combination of High- and Low-Frequency Transcutaneous Electrical Nerve Stimulation Reduces Mechanical Allodynia and Alters Dorsal Horn Neurotransmitter Content in Neuropathic Rats

The purpose of the study was to examine the effect of 3 different application strategies for transcutaneous electrical nerve stimulation (TENS) on neuropathy-induced allodynia and dorsal horn neurotransmitter content. Rats were treated with high-frequency, low-frequency, or a combination of high and low-frequency stimulation. TENS was delivered through self-adhesive electrodes daily for 1 hour to rats with a right-sided chronic constriction injury (CCI). Stimulation was delivered to skin or acupuncture points on the left and mechanical and thermal pain thresholds were assessed in the right hind paw. Neurotransmitter content was assessed bilaterally in the dorsal horn of the spinal cord. Daily, high-frequency or a combination of high- and low-frequency TENS reduced mechanical (P < .001), but not thermal allodynia in the right hind paw when compared with untreated CCI rats. Daily high frequency TENS elevated the dorsal horn synaptosomal content of GABA bilaterally (P < .014) and a combination of high- and low-frequency TENS elevated the dorsal horn content of aspartate (P < .001), glutamate (P < .001) and glycine (P < .001) bilaterally over that seen in untreated CCI rats. The present findings support a contralateral approach to the application of TENS and suggest that distinct strategies for TENS application may differentially alter neurotransmission in the central nervous system.PerspectiveBecause CCI rats are reminiscent of humans with neuropathy, daily high or a combination of high- and low-frequency TENS may reduce mechanical allodynia in humans with neuropathic pain. Because the 2 intervention strategies produce distinctive alterations in spinal cord neurotransmitter content, each may represent a distinctive option for treatment.     

Vitamin C transporter Slc23a1 links renal reabsorption,vitamin C tissue accumulation,and perinatal survival in mice

Levels of the necessary nutrient vitamin C (ascorbate) are tightly regulated by intestinal absorption, tissue accumulation, and renal reabsorption and excretion. Ascorbate levels are controlled in part by regulation of transport through at least 2 sodium-dependent transporters: Slc23a1 and Slc23a2 (also known as Svct1 and Svct2, respectively). Previous work indicates that Slc23a2 is essential for viability in mice, but the roles of Slc23a1 for viability and in adult physiology have not been determined. To investigate the contributions of Slc23a1 to plasma and tissue ascorbate concentrations in vivo, we generated Slc23a1^–/– mice. Compared with wild-type mice, Slc23a1^–/– mice increased ascorbate fractional excretion up to 18-fold. Hepatic portal ascorbate accumulation was nearly abolished, whereas intestinal absorption was marginally affected. Both heterozygous and knockout pups born to Slc23a1^–/– dams exhibited approximately 45% perinatal mortality, and this was associated with lower plasma ascorbate concentrations in dams and pups. Perinatal mortality of Slc23a1^–/– pups born to Slc23a1^–/– dams was prevented by ascorbate supplementation during pregnancy. Taken together, these data indicate that ascorbate provided by the dam influenced perinatal survival. Although Slc23a1^–/– mice lost as much as 70% of their ascorbate body stores in urine daily, we observed an unanticipated compensatory increase in ascorbate synthesis. These findings indicate a key role for Slc23a1 in renal ascorbate absorption and perinatal survival and reveal regulation of vitamin C biosynthesis in mice.     

老年脑梗塞血小板膜Ts含量与血脂血糖及血钙相关分析

目的：研究５０例老年急性脑梗塞患者血浆中血小板膜凝血酶敏感蛋白（Ｔｈｒｏｍｂｓｐｏｎｄｉｎ,Ｔｓ）与部分生化指标改变的相关性,有利于制定急性脑梗塞早期防治措施。方法：采用流式细胞仪测定Ｔｓ,生化指标用５０８型生化自动分析仪检测。结果：脑梗塞组血浆中血小板膜Ｔｓ与甘油三酯胆固醇、血糖、血钙相关良好,相关系数分别在０．３３、０．３４、０．３１、０．５６以上,Ｐ＜０．０５。而脑动脉硬化组相关系数分别为０．１４、０．１６、０．０７、０．０７,Ｐ＞０．０５。结论：Ｔｓ是血小板膜上α－颗粒蛋白,表达于激活后血小板表面,血浆中Ｔｓ含量增高值与上述生化指标正相关性改变参与脑梗塞形成机制。     

Vitamin C attenuates potassium dichromate-induced nephrotoxicity and alterations in renal brush border membrane enzymes and phosphate transport in rats

BACKGROUND: Exposure to chromium compounds can result in nephrotoxicity. The administration of potassium dichromate (K(2)Cr(2)O(7)), a hexavalent chromium compound, results in impairment in functions of renal brush border membrane (BBM). METHODS: The effect of vitamin C (ascorbic acid) on K(2)Cr(2)O(7)-induced nephrotoxicity, changes in BBM enzymes, Pi transport and the anti-oxidant status of rat kidney were studied. Animals were divided into 4 groups and were intraperitoneally given saline (control), vitamin C alone, K(2)Cr(2)O(7) alone and vitamin C plus K(2)Cr(2)O(7). Nephrotoxicity was evaluated by urea and creatinine levels in the serum. Anti-oxidant status was evaluated in kidney homogenates. RESULTS: A single dose of K(2)Cr(2)O(7) (15 mg/kg body weight) resulted in an increase of serum urea nitrogen and creatinine levels, increase in lipid peroxidation and decrease in total sulfhydryl groups. However, prior treatment with a single dose of vitamin C (250 mg/kg body weight) protected the kidney from the damaging effects of K(2)Cr(2)O(7). It greatly ameliorated the K(2)Cr(2)O(7)-induced nephrotoxicity and reduction in Pi transport, activities of catalase, Cu-Zn superoxide dismutase and BBM enzymes. This was accompanied by decrease in lipid peroxidation and recovery of sulfhydryl content of renal cortex. CONCLUSIONS: Vitamin C is an effective chemoprotectant against K(2)Cr(2)O(7)-induced acute renal failure and dysfunction of the renal BBM in rats.