The levels of some antioxidant vitamins,glutathione peroxidase and lipoperoxidase during the anaesthesia of dogs

The aim of this investigation was to determine serum levels of vitamin A, E, beta carotene, glutathione peroxidase (GSHPx), lipid peroxidation (MDA) and biochemical and haematological parameters during enflurane anaesthetised dogs. Ten kangal dogs were used and all animals were anaesthetised with enflurane for two hours and blood samples were taken before and 30, 120 minutes, 24 hours and 7 days during the anaesthesia. Vitamin E and beta carotene content were significantly (p<0·05 and p<0·01) higher before anaesthesia than after whereas serum GSHPx activity was not statistically different. However, serum levels of vitamin A and MDA were significantly (p<0·05) increased during the anaesthesia. In general, serum levels of aspartate aminotransferase, alanine aminotransferase, albumin, glucose, urea and creatinine were significantly (p<0·05 and p<0·01) increased during anaesthesia and returned to near normal values after 7 days of anaesthesia, whereas the white blood cell count was significantly (p<0·05 and p<0·01) decreased during the anaesthesia. However, the red blood cell count, haemoglobin and packed cell volume values, and levels of total cholesterol, triglycerides, total protein and globulin were apparently not influenced by the anaesthesia. In conclusion, we observed that the serum level of vitamin E and beta carotene were significantly decreased, whereas serum MDA and vitamin A levels were significantly increased during the enflurane anaesthesia. Copyright © 1999 John Wiley & Sons, Ltd.     

Kinetics of tissue RRR-alpha-tocopherol depletion and repletion. Effect of cold exposure

Vitamin E was estimated in plasma and tissues of rats kept for three months on a low vitamin E diet or a high vitamin E diet. Some of the animals from each group were switched to the opposite diet, and the kinetics of uptake and depletion of vitamin E were followed 3, 8, and 15 days after the diet change. Some rats were also submitted to cold exposure (6 degrees C) for three days. During repletion plasma, red blood cells, liver, spleen, and adrenal gland were the only tissues that responded rapidly to the diet change; after three days, their vitamin E levels corresponded to that of the new diet. Heart, brain, lung, muscle, and thymus were slow in reacting to diet change. Fifteen days after the change in diet, white adipose tissue did not respond. The rate of repletion for all tissues was more rapid than the rate of depletion, but liver was the only tissue that after three days had vitamin E levels corresponding to the low-vitamin diet. Cold exposure for three days did not produce any significant change in the vitamin E content of any tissue, indicating that despite high oxygen consumption by the animal, vitamin E was not consumed or mobilized.     

Blood plasma levels of lipoperoxides,glutathione peroxidase,beta carotene,vitamin A and E in women with habitual abortion

The plasma levels of lipoperoxides, glutathione peroxidase (GSH-Px), reduced glutathione (GSH), beta carotene, vitamin A, E, some plasma biochemical and blood haematological parameters were investigated in 40 women with habitual abortion (HA) and controls. The levels of GSH, vitamin A, E and beta carotene were significantly lower in women with HA than in controls. However, the plasma levels of lipid peroxidation, alkaline phosphatase (ALP), glucose and blood haemoglobin were significantly higher in HA than in controls. In addition, plasma levels of GSH-Px, AST, ALT, total bilirubin, total protein, albumin, sodium, potassium, calcium and number of white blood cells, red blood cells, platelet and values of packet cell volume showed no significant differences between HA and controls. According to the results of this study, we observed that the levels of lipid peroxidation were increased and plasma levels of vitamin A, E and beta carotene were decreased in HA. The decrease of those antioxidants may play a significant role in women with habitual abortion. Copyright © 1998 John Wiley & Sons, Ltd.     

Randomised controlled trial of effect of fruit and vegetable consumption on plasma concentrations of lipids and antioxidants.

OBJECTIVES: To determine the extent to which plasma antioxidant concentrations in people with habitual low intake of fruit and vegetables respond to increased intakes of these foods. To examine whether advice to increase fruit and vegetables will result in reduction of concentrations of total and low density lipoprotein cholesterol. DESIGN: Randomised controlled trial in which intervention and control groups were followed up for eight weeks. The intervention group was asked to consume eight servings of fruit and vegetables a day. SETTING: Dunedin, New Zealand. SUBJECTS: Eighty seven subjects with normal lipid concentrations who ate three or fewer servings of fruit and vegetables daily. MAIN OUTCOME MEASURES: Plasma concentrations of vitamin C, retinol, alpha and beta carotene, alpha tocopherol, lipids, and lipoproteins. Dietary intake assessed with diet records over four days. RESULTS: The mean plasma vitamin C, alpha carotene, and beta carotene concentrations increased in parallel with increased dietary intake of fruit and vegetables in the intervention group. Concentrations of retinol, alpha tocopherol, lipids, and lipoproteins remained unchanged despite some increase in dietary vitamin E and a small reduction in saturated fat intake. CONCLUSIONS: Following a recommendation to increase fruit and vegetable consumption produces change in plasma concentrations of vitamin C, alpha carotene, and beta carotene likely to reduce incidence of cancer. More specific dietary advice to modify fat intake may be necessary to reduce the risk of cardiovascular disease mediated by lipoprotein and vitamin E.     

Age-related changes of serum lipoprotein oxidation in rats

Oxidation of low-density lipoprotein (LDL) may be a prelude to atherogenesis and directly age related. To assess whether there may be relationship between age and plasma lipoprotein (LP) oxidation, we studied copper-mediated LP oxidation isolated from the blood of 2 months, 7 months, and 15 months old rats. We determined whether the susceptibility of LP to oxidation might be related to vitamin C levels in serum, vitamin E levels in LP, or the total antioxidant capacity (TAC) of serum or LP. Serum vitamin C content was inversely related to age, malondialdehyde (MDA) propagation rate, and maximum change of MDA concentrations. However, there were no significant relationships between age and serum TAC, LP TAC, serum vitamin E, or the ratio of LP vitamin E to serum vitamin C content. The lag phase of MDA formation was significantly decreased with age and the ratio of LP vitamin E content to serum vitamin C content, increased with age. Maximum change of MDA concentration was positively correlated with the ratio of LP vitamin E contents to serum vitamin C concentration. Thus, as the rat ages, vitamin C status decreases with an increased LP susceptibility to oxidation. It is tempting to speculate that enhanced LP oxidation in older rats may reflect a reduced amount of recycling of LDL vitamin E by serum vitamin C.     

Dietary vitamins A and E influence retinyl ester composition and content of the retinal pigment epithelium

Experiments were conducted to determine the influence of dietary levels of vitamin A and alpha-tocopherol on the amounts and composition of retinyl esters in the retinal pigment epithelium of light-adapted albino rats. Groups of rats were fed diets containing alpha-tocopherol and either no retinyl palmitate, adequate retinyl palmitate, or excessive retinyl palmitate. Other groups of rats received diets lacking alpha-tocopherol and containing the same three levels of retinyl palmitate. Retinoic acid was added to diets lacking retinyl palmitate. After 27 weeks, the animals were light-adapted to achieve essentially total visual pigment bleaches, and the neural retinas and retinal pigment epithelium-eyecups were then dissected from each eye for vitamin A ester determinations. Almost all of the retinyl esters were found in the retinal pigment epithelium-eyecup portions of the eyes, mainly as retinyl palmitate and retinyl stearate. Maintaining rats on a vitamin A-deficient, retinoic acid-containing diet led to significant reductions in retinal pigment epithelial retinyl ester levels in rats fed both the vitamin E-supplemented and vitamin E-deficient diets; contrary to expectations, the effect of dietary vitamin A deficiency was more pronounced in the vitamin E-supplemented rats. Vitamin A deficiency in retinoic acid-maintained animals also led to significant reductions in retinyl palmitate-to-stearate ester ratios in the retinal pigment epithelia of both vitamin E-supplemented and vitamin E-deficient rats. Excessive dietary intake of vitamin A had little, if any, effect on retinal pigment epithelial retinyl ester content or composition. Vitamin E deficiency resulted in significant increases in retinal pigment epithelial retinyl palmitate content and in palmitate-to-stearate ester ratios in rats fed all three levels of vitamin A, but had little effect on retinal pigment epithelial retinyl stearate content. In other tissues, vitamin E deficiency has been shown to lower vitamin A levels, and it is widely accepted that this effect is due to autoxidative destruction of vitamin A. The increase in retinal pigment epithelial vitamin A ester levels in response to vitamin E deficiency indicates that vitamin E does not regulate vitamin A levels in this tissue primarily by acting as an antioxidant, but rather may act as an inhibitor of vitamin A uptake and/or storage. The effect of vitamin E on pigment epithelial vitamin A levels may be mediated by the vitamin E-induced change in retinyl palmitate-to-stearate ratios.     

Hepatoprotective effect of selenium and vitamin E in rabbits fed a high-fat diet.

The high-fat diet consisted of cholesterol, hydrogenated coconut oil, and cholic acid. In the blood serum and in liver homogenate lipid content, cholesterol, and triglycerides were assayed. Cytochrome P-450 concentration in liver microsomes was also estimated. In animals receiving selenium and vitamin E, the content of lipid fractions in the blood serum and liver homogenate fell, while the cytochrome P-450 content in the liver microsomes was markedly elevated. The intensified protective effect of vitamin E and selenium applied in combination against changes induced in the liver of animals receiving a HFD was confirmed by macroscopic and microscopic examination of the organ.     

维生素E对中华鳖幼鳖生长、肝脏维生素E以及血清皮质醇含量的影响

为探讨维生素E(VE)对中华鳖(Pelodiscus sinensis)幼鳖的生长、肝脏VE和血清皮质醇的影响，通过特定生长率、高压液相色谱法和放免法，我们测定了中华鳖幼鳖的生长、肝脏VE和血清皮质醇含量。发现VE添加量为1000和5000mg／kg的两组，能明显降低中华鳖幼鳖的生长。维生素E添加量为500、1000和5000mg／kg的三组，肝脏维生素E含量明显高于对照组，VE添加量在0—1000mg／kg的范围时，肝脏VE的含量随着饲料中VE含量的增加呈指数式增加，并且在VE添加量为5000kg／kg的一组基本达到饱和。维生素E添加量为0和50mg／kg的2组，其血清皮质醇的平均值明显高于维生素E添加量为250、500、1000和5000mg／kg的4组的平均值。上述结果表明：高剂量的VE降低了中华鳖幼鳖的生长和血清皮质醇的含量；在一定剂量范围内，肝脏VE随着饲料中VE含量的增加而升高。     

Vitamin E prevents exercise-induced DNA damage

The single cell gel test (SCG test or comet assay) was used to study DNA damage in peripheral white blood cells (WBC) of humans after a single bout of exhaustive exercise and the effect of vitamin supplementation. Human subjects were asked to run on a treadmill until exhaustion and blood samples were taken before and 24 h after the run. A clear increase in DNA strand breakage was observed in the 24-h sample of all probands. A short-term application of multivitamin pills or vitamin E (3 × 800 mg) resulted in a significantly smaller increase of DNA effects in WBC of some probands. When the volunteers were given a supplement of vitamin E (1200 mg daily) for 14 days prior to run, exercise-induced DNA damage was clearly reduced in all probands. In four out of five subjects, vitamin supplementation completely prevented the induction of DNA damage after exhaustive exercise. Intake of vitamin E for 14 days led to a clear increase in vitamin E serum concentrations. Malondialdehyde (MDA), a marker of lipid peroxidation, was measured in the serum of probands in tests with and without vitamin supplementation for 14 days. MDA concentrations were significantly decreased following vitamin E supplementation but not significantly changed 15 min and 24 h after a run. Our results demonstrate that vitamin E prevents exercise-induced DNA damage and indicate that DNa breakage occurs in WBC after exhaustive exercise as a consequence of oxidative stress.     

Serum Selenium,Vitamin E,and Sialic Acids Concentrations in Lambs with White Muscle Disease

The aim of this study was to determine the serum concentrations of selenium, vitamin E, and total- and lipid-bound sialic acid (LBSA) in lambs with white muscle disease (WMD) before and after treatment with a commercial preparation containing selenite and vitamin E. Fifteen lambs with WMD and ten control animals were used as research materials. Blood samples were collected from both groups before- and 1 month after treatment for Se analysis by fluorimetry, whereas vitamin E and sialic acid were measured by HPLC and spectrophotometry, respectively. Compared to controls, in the diseased animals, there was a significant increase of serum total sialic acid (TSA) and LBSA, together with significant decreases of serum Se and vitamin E concentrations (p < 0.001). One month after treatment, a reversal of trend was observed with decreases of TSA and LBSA and increases of Se and vitamin E concentrations. The TSA and LBSA levels, however, remained significantly higher than those of the controls, p < 0.05 and 0.001, respectively. The Se and vitamin E concentrations of the treated animals were the same as those of controls. This is the first study on total and LBSA concentrations in lambs with WMD, showing that these markers can be used in the prognosis of the disease.     

17β-Estradiol and Vitamin E Modulates Oxidative Stress-Induced Kidney Toxicity in Diabetic Ovariectomized Rat

The aim of this study was to investigate the effects of vitamin E (alpha-tocopherol) and 17β-estradiol (E(2)) supplementation on malondialdehyde (MDA), glutathione (GSH), vitamin A, beta carotene, selenium-dependent glutathione peroxidase (GSH-Px), zinc-dependent superoxide dismutase (SOD), and copper/zinc-dependent catalase (CAT) values in the kidney of ovariectomized (OVX) diabetic rats. Forty-two female rats were randomly divided into seven equal groups as follows: group I, control; group II, OVX; group III, OVX+E(2); group IV, OVX+E(2)+alpha-tocopherol; group V, OVX+diabetic; group VI, OVX+diabetic+E(2); and group VII, OVX+diabetic+E(2)+alpha-tocopherol. E(2) (40?μg?kg(-1)/day) and alpha-tocopherol (100?μg?kg(-1)/day) were given. Bilateral ovariectomy was performed in all groups except group I. After 4?weeks, antioxidant and MDA levels in the kidney for all groups were analyzed. GSH-Px, CAT, SOD, GSH levels, vitamin A, and beta carotene levels were decreased in OVX group compared to those in the control group but MDA level was elevated via ovariectomy. However, E(2) and E(2)+alpha-tocopherol supplementations in OVX group was associated with an increase in the GSH-Px, GSH, CAT and Zn-SOD values, vitamin A, and beta carotene levels but a decrease in MDA levels in kidney. The MDA levels in the kidney of diabetic OVX rats were found higher than those in the control and OVX groups. However, GSH, GSH-Px, CAT, SOD, vitamin A, and beta carotene levels in kidney were lower in OVX diabetic rats. On the other hand, E(2) and E(2)+alpha-tocopherol supplementations to OVX diabetic rats have caused an increase in GSH-Px, CAT and SOD, GSH, vitamin A, and beta carotene levels but a decrease in MDA levels. In conclusion, the E(2) and E(2)+alpha-tocopherol supplementations to diabetic OVX and OVX rats may strengthen the antioxidant defense system by reducing lipid peroxidation, and therefore they may play a role in preventing renal disorders.     

Increased lymphocyte antioxidant defences in response to exhaustive exercise do not prevent oxidative damage

It has been reported that exercise induces oxidative stress and causes adaptations in antioxidant defences. The aim of this study was to determine the adaptations of lymphocytes to the oxidative stress induced by an exhaustive exercise. Nine voluntary male subjects participated in the study. The exercise was a cycling mountain stage (171.8 km), and the cyclists took a mean of 283 min to complete it. Blood samples were taken the morning of the cycling stage day, after overnight fasting, and 3 h after finishing the stage. We determined the blood glutathione redox status (GSSG/GSH), lymphocyte antioxidant enzyme activities and superoxide dismutase (SOD) levels; the plasma and lymphocyte vitamin E levels; the serum lactate dehydrogenase (LDH) and creatine kinase (CK) activities and urate levels; the plasma carotene and malonaldehyde (MDA) levels; and the lymphocyte carbonyl index. The cycling stage induced significant increases in blood-oxidized (glutathione/GSSG), plasma MDA and serum urate levels. The exercise also produced increases in CK and LDH serum activities. The mountain cycling stage induced significant increases in lymphocyte vitamin E levels, glutathione peroxidase and glutathione reductase activities as well as increased SOD activity and protein levels. The protein carbonyl levels increased significantly in lymphocytes after the stage. In conclusion, in spite of increasing antioxidant defences in response to the oxidative stress induced by the exhaustive exercise, lymphocyte oxidative damage was produced after the stage as demonstrated by the increased carbonyl index even in very well trained athletes.     

Complete nutrient content of four species of commercially available feeder insects fed enhanced diets during growth

Commercially raised feeder insects used to feed captive insectivores are a good source of many nutrients but are deficient in several key nutrients. Current methods used to supplement insects include dusting and gut‐loading. Here, we report on the nutrient composition of four species of commercially raised feeder insects fed a special diet to enhance their nutrient content. Crickets, mealworms, superworms, and waxworms were analyzed for moisture, crude protein, fat, ash, acid detergent fiber, total dietary fiber, minerals, amino acids, fatty acids, vitamins, taurine, carotenoids, inositol, and cholesterol. All four species contained enhanced levels of vitamin E and omega 3 fatty acids when compared to previously published data for these species. Crickets, superworms, and mealworms contained β‐carotene although using standard conversion factors only crickets and superworms would likely contain sufficient vitamin A activity for most species of insectivores. Waxworms did not contain any detectable β‐carotene but did contain zeaxanthin which they likely converted from dietary β‐carotene. All four species contained significant amounts of both inositol and cholesterol. Like previous reports all insects were a poor source of calcium and only superworms contained vitamin D above the limit of detection. When compared to the nutrient requirements as established by the NRC for growing rats or poultry, these species were good sources of most other nutrients although the high fat and low moisture content of both waxworms and superworms means when corrected for energy density these two species were deficient in more nutrients than crickets or mealworms. These data show the value of modifying the diet of commercially available insects as they are growing to enhance their nutrient content. They also suggest that for most insectivores properly supplemented lower fat insects such as crickets, or smaller mealworms should form the bulk of the diet. Zoo Biol. 34:554–564, 2015. © 2015 The Authors. Zoo Biology published by Wiley Periodicals, Inc.     

Role of alpha-tocopherol and retinol in the antiradical protection of the body in peptic ulcer]

Retinol and tocopherol content, the intensity of spontaneous chemiluminescence as well as concentration of malonic dialdehyde in the blood of practically healthy persons of different age groups and in patients with gastric and duodenal ulcer have been studied. Results are presented. The lower content of tocopherol was revealed in the young persons as compared with other age groups, while the level of vitamin A was not established to depend on age. The content of tocopherol is established to decrease in the blood serum under peptic ulcer. Under these conditions low level of retinol correlates with considerable growth of spontaneous chemiluminescence. Reserve interrelation of tocopherol content in the blood with the level of spontaneous chemiluminescence as well as the absence of true dependence on the concentration of malonic dialdehyde at peptic ulcer are proved. Mechanisms of participation of vitamins E and A in the inhibition of free-radical reactions are discussed, role of their deficiency in pathogenesis fo peptic ulcer is substantiated.     

Prediction of Vitamin A,Vitamin E,Selenium and Zinc Status of Periparturient Dairy Cows Using Blood Sampling During the Mid Dry Period

Vitamins A and E, and the trace elements selenium (Se) and zinc (Zn) are essential for the health and performance of dairy cows. Their concentrations often decrease around calving and extra supplementation is sometimes recommended at that time. However, the need for this varies, for example depending on quantity and quality of feedstuffs in the diet. The aim of this study was to measure the concentrations of serum vitamin A (S-vit A) and vitamin E (S-vit E), plasma Se (P-Se) and serum Zn (S-Zn) in blood samples taken at several time points from one month before to one month after calving, and to evaluate if a blood sample taken during the mid dry period can accurately predict the blood concentration at calving and early lactation. Dairy cows on 3 different feeding regimens during the dry period were included in the study. A significant decrease in the concentrations of S-vit A and S-vit E, and S-Zn, was observed at calving, and P-Se was significantly lower during the dry period and at calving than in early lactation. The blood concentrations of S-vit E and P-Se in the mid dry period significantly predicted the occurrence of values considered marginal or deficient at the time of calving. The data indicate that a mid dry period concentration of ≥5.4 mg/l of S-vit E and ≥0.09 mg/l of P-Se will result in a 90% chance that the cow stays above marginal levels at calving given that a feed of the same quality is offered.     

The vitamin B 12 serum level at various ages]

A report is presented on the determination of the vitamin B12 content by means of radioassay in the serum of 402 healthy persons aged between 14 to 98 years. With increasing age a significant decrease of the vitamin B12 content could be observed in both sexes after the sixtieth year of age. In the age group between 21 to 30 only the low values of women made an exception, which may be due to the administration of contraceptives.     

Biochemical and clinical effects of an antioxidative supplementation of geriatric patients

Ninety seven geriatric patients from two Danish homes for old people accepted to participate in a blinded experiment designed to counteract ageing phenomena. The subjects were split into two groups, i.e., the verum and the placebo group. The verum group received daily for one year an antioxidative cocktail consisting of: 300 micrograms selenium as L-selenomethionine, 45 mg zinc, 270 mg vitamin C, 2.7 mg vitamin A, 6 mg vitamin B-6, and 465 mg vitamin E (d-alfatocopherol). Furthermore, in order to enhance exchange in polyenoic acids, each subject received daily 250 mg gamma-linolenic acid. The placebo groups received similar looking pills and capsules without the active components. During one year in the verum group, the whole blood selenium, the hydrogen-dependent glutathione peroxidase (GSH-Px) of erythrocytes, and the vitamin E level in serum was found increased compared to the pretreatment values and to the placebo group. No change could be traced in the t-butylhydroperoxide dependent GSH-Px, an enzyme that also assays the glutathione-s-transferase. During the same period of time, the fasting levels of serum fatty acids and the content of lipofuscin in erythrocytes were estimated. Compared to the pretreatment values, the lipofuscin level declined significantly and the level of w-3 penta- and hexaenoic acids increased in the verum, but not in the placebo group. During the study period, slight, but significant improvements in psychological scores could be traced. Furthermore, the assays of bloodflow in different areas of the brain surface (i.e., the ISI values) revealed a general trend to improvement in all areas, when the ISI values were compared during treatment with the pretreatment values and the values in the placebo group.     

Effects of a carotene-deficient diet on measures of oxidative susceptibility and superoxide dismutase activity in adult women

The effect of consuming a low carotene diet (≈60 μg carotene/day) on oxidative susceptibility and superoxide dismutase (SOD) activity in women living in a metabolic research unit was evaluated. The diet had sufficient vitamins A, E, and C. The women ate the diet supplemented with 1500 μg/day β-carotene for 4 days (baseline), then the unsupplemented diet for 68 days (depletion), followed by the diet supplemented with > 15,000 μg/day carotene for 28 days (repletion). Production of hexanal, pentanal, and pentane by copper-oxidased plasma low density lipoproteins from carotene-depleted women was greater than their production of these compounds when repleted with carotene. Erythrocyte SOD activity was depressed in carotene-depleted women; it recovered with repletion. Thiobarbituric acid reactive substances in plasma of carotene-depleted women were elevated and diminished with repletion. Dietary carotene seems to be needed, not only as a precursor of vitamin A, but also to inhibit oxidative damage and decrease oxidation susceptibility.     

Serum iron and copper status and oxidative stress in severe and mild preeclampsia

Our aim was to investigate parameters of iron and copper status and oxidative stress and antioxidant function in women with healthy pregnancy, mild and severe preeclampsia with a view to exploring the possible contribution of these parameters to the aetiology. Thirty healthy, 30 mild preeclamptic and 30 severe preeclamptic pregnant women were included. Serum and placental lipid peroxides, and serum vitamin E and total carotene levels were measured by colorimetric assay. Cholesterol, copper, iron, total iron binding capacity (TIBC), ceruloplasmin and transferrin concentrations were measured by commercially available procedures. Data were analysed statistically using one-way analysis of variance and Pearson correlation test. Logistic regression procedures were used to calculate odds ratios. Lipid peroxides in serum and placental tissue, and iron, copper and ceruloplasmin levels in serum were significantly increased, and transferrin, TIBC, vitamin E/total cholesterol and total carotene/total cholesterol ratios in serum were significantly decreased especially in women with severe preeclampsia. Significant correlations were detected between serum iron and lipid peroxides in serum and placental tissue and between serum iron and vitamin E/total cholesterol in severe preeclamptic pregnancy. Furthermore, there were significant correlations between serum malondialdehyde and ceruloplasmin and vitamin E/total cholesterol in women with severe preeclampsia, and changes in serum and placental lipid peroxides and serum iron concentrations were significantly associated with preeclampsia. In conclusion, ischaemic placental tissue may be a primary source of potentially toxic iron in preeclampsia and the released iron species may contribute to the aetiology and would exacerbate lipid peroxidation and endothelial cell injury, which may be abated by antioxidant supplementation.     

Effect of vitamin E therapy on serum uric acid in DOCA-salt-treated rats

Uric acid is considered as an antioxidant in the blood. Despite its proposed protective properties, elevated plasma uric acid has been associated with hypertension in a variety of disorders. The purpose of this study was to investigate the relationship between the increase of arterial blood pressure and the changes in serum uric acid, measured during the gradual development of experimental hypertension in deoxycorticosterone (DOCA)-salt-treated rats. Blood pressure was monitored by tail-cuff method, urinary and plasma uric acid was measured by autoanalyzer during the induction of hypertension in 1-, 2-, 3- and 4-week DOCA-salt-treated Sprague-Dawley rats. Vitamin E (200 mg/kg/day/gavage) was co-administered with DOCA-salt for 4 weeks. From the first week of DOCA-salt treatment, rats exhibited marked increases in blood pressure. DOCA-salt treatment also resulted in a significant increase in serum uric acid and a significant decrease in urinary uric acid at the end of the first week. These changes in serum and urinary uric acid remained until the 4th week of DOCA-salt treatment but blood pressure continued to increase throughout the study. Vitamin E treatment increased urinary excretion of uric acid and decreased blood pressure and serum uric acid in DOCA-salt-treated rats. These data suggest that enhanced serum uric acid may be a contributing factor to the onset of hypertension in DOCA-salt-treated rats. A uricosuric effect is suggested for vitamin E in the treatment of hypertension.