首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
目的:探讨维生素E(VE)在青年和老年大鼠肾缺血/再灌注损伤(RI/RI)中的作用。方法:采用夹闭双侧肾动、静脉45min后恢复血流的方法制作RI/RI模型,测定血清中尿素氮(BUN)、肌酐(Scr)、丙二醛(MDA)、超氧化物歧化酶(SOD)、一氧化氮(NO)、诱生型一氧化氮合酶(iNOS)浓度,免疫组化检测肾皮质热休克蛋白70(HSP70)表达。流式细胞术检测肾皮质细胞凋亡率。结果:缺血/再灌注(I/R)后BUN、Scr含量明显升高,老年I/R组MDA含量高于青年I/R组,SOD含量低于青年IR组,HSP70、NO以及肾皮质细胞凋亡率高于control组;VE可显著降低RI/RI大鼠BUN、Scr、MDA、iNOS水平,升高NO和SOD水平,增加HSP70的表达,降低肾皮质细胞凋亡率。结论:VE可通过促进肾组织HSP70的表达,增加NO和SOD水平,提高大鼠体内清除自由基的能力,从而对青、老年大鼠肾缺血/再灌注损伤(RI/RI)起到一定的保护作用。  相似文献   

2.
Initial experiments were conducted using an in situ rat tibialis anterior (TA) muscle preparation to assess the influence of dietary antioxidants on muscle contractile properties. Adult Sprague-Dawley rats were divided into two dietary groups: 1) control diet (Con) and 2) supplemented with vitamin E (VE) and alpha-lipoic acid (alpha-LA) (Antiox). Antiox rats were fed the Con rats' diet (AIN-93M) with an additional 10,000 IU VE/kg diet and 1.65 g/kg alpha-LA. After an 8-wk feeding period, no differences existed (P > 0.05) between the two dietary groups in maximum specific tension before or after a fatigue protocol or in force production during the fatigue protocol. However, in unfatigued muscle, maximal twitch tension and tetanic force production at stimulation frequencies < or = 40 Hz were less (P < 0.05) in Antiox animals compared with Con. To investigate which antioxidant was responsible for the depressed force production, a second experiment was conducted using an in vitro rat diaphragm preparation. Varying concentrations of VE and dihydrolipoic acid, the reduced form of alpha-LA, were added either individually or in combination to baths containing diaphragm muscle strips. The results from these experiments indicate that high levels of VE depress skeletal muscle force production at low stimulation frequencies.  相似文献   

3.
In the present investigation, we have used adenosine triphosphatase (ATPase) activity as biochemical test of toxic action of lindane that was explained by lipid peroxidation model. Study was also undertaken to ascertain the potential protective role of alpha-lipoic acid (ALA) and vitamin E on the same parameters. Highly acute dose of lindane, i.e., 40 mg/kg bw for 18 h exposure, was used for creating lesions in brain. Lipid peroxidation was measured in terms of glutathione peroxidase and thio barbituric acid-reacting substances (TBARS). Various brain regions under investigation were cerebellum and pons-medulla oblongata. Healthy, male, Swiss mice (7–8 weeks old) were allocated into four groups. First group was control, second group was treated with lindane, third group was treated purely with antioxidants, and fourth group received both antioxidants and lindane treatment. Results revealed the significant difference (at 1% and 5% in all groups) in all studied parameters from control. Increased TBARS level in second group suggests that lindane enhances the production of free radicals in studied brain regions. Antioxidants under test are efficient remedy for neurotoxicity caused by lindane. We conclude that lindane manifests toxic effects on brain ATPase and enhances lipid peroxidation. ALA and vitamin E in combination may provide protection against lindane-induced acute toxicity.  相似文献   

4.
5.
Redistribution of selenium and manganese in postmitotic tissues of alpha-lipoic acid-supplemented aged rats has been proposed to contribute to metal-catalyzed protein oxidation. DL-Alpha-lipoic acid (LA) (100 mg/[kg body wt.day]) was administered intraperitoneally to the Sprague-Dawley rats for 14 days. Serum selenium levels were lowered in the aged rats with LA supplementation compared with those of the rats without LA supplementation. Similarly, the selenium levels of the heart, brain and muscle were found to be significantly lower in LA-supplemented rats when compared to control rats. On the other hand, serum manganese levels were not changed in the aged rats with LA supplementation compared with those of the rats without LA supplementation. The heart manganese levels detected in LA-supplemented rats were significantly lower than controls. Manganese levels of the brain and muscle tissues were increased in the aged rats with LA supplementation compared with those of the rats without LA supplementation. Based on the findings of our study, we conclude that LA may exhibit pro-oxidant effect depending on the altered selenium and manganese homeostasis. Thus, our results stress the importance of monitoring the dose of LA supplementation and serum selenium levels, duration of treatment and its potential harmful pro-oxidant effects in the postmitotic tissues of aged rats.  相似文献   

6.
Carbon centered and hydrogen radicals were examined using electron spin resonance techniques with 5,5 dimethyl-2-pyrroline-1-oxide in the skeletal muscle of rats fed with a control diet and a vitamin E supplemented diet containing alpha tocopherol. Carbon centered and hydrogen radical levels in the white and red muscles and the soleus of these vitamin E treated muscle fibers were decreased. These results suggest that vitamin E directly quenches these free radicals.  相似文献   

7.
The aim of this research was to examine the effects of a triple antioxidant combination (vitamins E (VE) and C (VC) plus alpha-lipoic acid (LA)) on the total lipid and cholesterol levels and the fatty acid composition of brain tissues in experimental diabetic and non-diabetic rats. VE and LA were injected intraperitoneally (50 mg/kg) four times per week and VC was provided as a supplement dissolved in the drinking water (50 mg/kg). In addition, rats in the diabetes 1 and D+VELAVC groups were given daily by subcutaneous insulin injections (8 IU/kg), but no insulin was given to rats in the diabetes 2 group. The results indicate that the brain lipid levels in the D+VELAVC, diabetes 1 and diabetes 2 groups were higher than in the control group (P<0.01). Total lipid was also higher in the non-diabetic rats treated with LA and VC. Total cholesterol was higher in the diabetes 1 and diabetes 2 groups (P<0.05) than in controls. Cholesterol levels were similar in the D+VELAVC and LA groups but lower in the VC, VE and VELAVC groups of non-diabetic rats (P<0.05 and P<0.01). In respect of fatty acid composition, palmitic acid levels were lower in the diabetes 2 and non-diabetic VE groups than the control group (P<0.05), but higher in the non-diabetic LA group (P<0.05). Oleic acid (18:1 n-9) levels were lower in the diabetic and non-diabetic groups than the control group (P<0.01), but higher in the non-diabetic LA group. Arachidonic acid (20:4 n-6) levels were similar in the diabetes 1, D+VELAVC and control groups (P>0.05) but higher in the non-diabetic VE, VC, LA and VEVCLA groups (P<0.05) and lower in the diabetes 2 group (P<0.05). Docosahexaenoic acid (22:6 n-3) was elevated in the diabetes 2 and VEVCLA groups (P<0.01, P<0.05). In conclusion, the current study confirmed that treatment with a triple combination of VE, VC and LA protects the arachidonic acid level in the brains of diabetic and non-diabetic rats.  相似文献   

8.
Effect of exercise on cardiac muscle performance in aged rats   总被引:1,自引:0,他引:1  
Most investigations of a direct impact of chronic physical conditioning on cardiac muscle physiology and biochemistry have utilized relatively young animal models. Some, but not all, of these studies have demonstrated beneficial effect of relatively modest magnitude. With advancing age, i.e., with the onset of senescence, characteristic changes in many aspects of cardiac physiology and biochemistry in rodent models have been noted to occur. In general, these consist of a reduction in the kinetics of events that determine myocardial excitation-contraction relaxation and energetics. Recently it has been shown that several of these apparent age-related functional declines can be reversed by chronic physical conditioning, which in some instances have no effect on cardiac muscle of younger animals. This suggests that the relative efficacy of chronic exercise to modulate myocardial performance may, in part, be determined by the level of function present before the intervention, as is the case for other modulators of cardiac muscle function. In addition, that apparent age-related deficits in myocardial function can be reversed by conditioning suggests an interaction between life-style and aging.  相似文献   

9.
Vitamin A (VA) metabolism in neonates is virtually uncharacterized. Our objective was to develop a compartmental model of VA metabolism in unsupplemented and VA-supplemented neonatal rats. On postnatal day 4, pups (n = 3/time) received 11,12-[3H]retinol orally, in either oil (control) or VA combined with retinoic acid (VARA) [VA (∼6 mg/kg body weight) + 10% retinoic acid]. Plasma and tissues were collected at 14 time points up to 14 days after dose administration. VARA supplementation rapidly, but transiently, increased total retinol mass in plasma, liver, and lung. It decreased the peak fraction of the dose in plasma. A multi-compartmental model developed to fit plasma [3H]retinol data predicted more extensive recycling of retinol between plasma and tissues in neonates compared with that reported in adults (144 vs. 12–13 times). In VARA pups, the recycling number for retinol between plasma and tissues (100 times) and the time that retinol spent in plasma were both lower compared with controls; VARA also stimulated the uptake of plasma VA into extravascular tissues. A VARA perturbation model indicated that the effect of VARA in stimulating VA uptake into tissues in neonates is both dramatic and transient.  相似文献   

10.
Thirty New Zealand white rabbits, mean weight 2 kg, were divided into three equal groups balanced for body weight and randomly assigned to a diet containing 60 (C), 150 (T1) or 375 (T2) mg/kg of all-rac-alpha-tocopheryl acetate. After 29 days, the animals were slaughtered. alpha-Tocopherol was assayed in muscle (longissimus dorsi) and plasma; triglycerides and cholesterol (total, high density lipoprotein, low density lipoprotein) were analysed in plasma; reactive oxygen metabolites (ROMs) were analysed in serum; and thiobarbituric acid-reactive substances (TBARS) were analysed in muscle. There were no body weight and food intake differences between the groups. The plasma vitamin E and vitamin E:lipid ratio were significantly higher in groups T1 and T2 than in C, but increases were not linearly related to dietary levels. Muscle alpha-tocopherol concentrations in the treated groups were significantly higher than in C, and linearly related (R =.67) to the vitamin E:lipid ratio. ROM and vitamin E levels in blood were inversely related (R =.74), with ROMs significantly lower in the treated groups than in C. The 60-mg/kg dose of C recommended by the National Research Council was unable to control ROM production. Lipid oxidation in muscle was significantly lower in T2 than in the other groups, and TBARS correlated significantly with muscle vitamin E (R =.61) and serum ROM (R =.73). These data suggest that vitamin E supplemented at 375 mg/kg diet can effectively control ROM production and improve muscle lipostability. ROM assay provides a useful indirect estimate of the oxidative status of muscle in vivo.  相似文献   

11.
Helmy MM  Senbel AM 《Life sciences》2012,90(13-14):489-494
AimsThe present study aims to elucidate the role of oxidative stress in erectile dysfunction associated with aging and to investigate the effect of treatment with vitamin E in this respect.Main methodsRats were divided into four groups: young (3-month-old), aged rats (18-month-old), aged rats given 80 IU of vitamin E/rat/day for 21-days, aged rats given 5 mg/kg of sildenafil/day for 21-days. Intracavernosal pressure/mean arterial pressure (ICP/MAP), nitric oxide production, TBARS, GSH levels and SOD activity in corpus cavernosum were measured.Key findingsSignificant decrease in ICP/MAP was observed in aged rats at both low and high frequency of stimulation. Significant increase in ICP/MAP was observed in aged rats treated with vitamin E over the range of 0.8 to 5 Hz but young control values were not restored. Percentage potentiation of ICP/MAP than aged group at 0.8 Hz was 326 ± 41.3% and 897 ± 72.2% for vitamin E and sildenafil respectively. Decreased levels of NO2/NO3 and SOD activity in the penile tissue observed with aging were elevated back to control by either vitamin E or sildenafil. Penile concentration of TBARS was 20.86 ± 0.83 for aged rats vs. 11.39 ± 0.79 nmol/g tissue for young controls. Both vitamin E and sildenafil reduced penile TBARS in aged rats.SignificanceThis study proves that antioxidant therapy with vitamin E ameliorates the age-associated erectile dysfunction. Sildenafil may exert some antioxidant properties which add to the advantages of its long-term use. The effect of combinations of low-dose sildenafil and vitamin E on age-associated erectile dysfunction merits to be studied.  相似文献   

12.
In this study we have evaluated the supplementation of olive oil with vitamin E on coenzyme Q concentration and lipid peroxidation in rat liver mitochondrial membranes. Four groups of rats were fed on virgin olive, olive plus 200 mg/kg of vitamin E or sunflower oils as lipid dietary source. To provoke an oxidative stress rats were administered intraperitoneally 10 mg/kg/day of adriamycin the last two days of the experiment. Animals fed on olive oil plus vitamin E had significantly higher coenzyme Q and vitamin E levels but a lower mitochondrial hydroperoxide concentration than rats fed on olive oil. Retinol levels were not affected, by either different diets or adriamycin treatment. In conclusion, an increase in coenzyme Q and alpha-tocopherol in these membranes can be a basis for protection against oxidation and improvement in antioxidant capacity.  相似文献   

13.
Mitigation of lindane induced toxicity in testis of Swiss mice by combined treatment with vitamin C, vitamin E and alpha-lipoic acid has been evaluated. Male healthy mice (40), 8-10 weeks old were randomly selected and divided into 4 groups, control (C); lindane (L); antioxidant (A) and antioxidant plus lindane (A+L). Group C animals were administered only the vehicle (olive oil); in group L lindane was administered orally at a dose of 40 mg/kg body wt.; in group A combination of antioxidants at a dose of 125 mg/kg body wt.(vitamin C: 50 mg/kg body wt., vitamin E: 50 mg/kg body wt. and alpha-lipoic acid: 25 mg/kg body wt.) was administered orally; in group A+L both antioxidants (125 mg/kg body wt.) and lindane (40 mg/kg body wt.) were administered at their respective doses. In group A+L antioxidants were administered 1 h prior to lindane administration. All treatments were continuously given for 60 days. Histopathological changes due to lindane intoxication indicated shrunken and distorted seminiferous tubules, sparse Leydig cells and blood vessels and atrophy in the tissue. The testis weight also decreased significantly. Lindane treated group showed increased lipid peroxidation, whereas glutathione, glutathione peroxidase, superoxide dismutase, catalase and protein were significantly decreased compared to control. Lindane induced damage was minimized by administration of antioxidants. Results suggest that combined pretreatment with antioxidants can alleviate the damage caused to testis by lindane.  相似文献   

14.
The widely conserved preferential accumulation of α-tocopherol (α-TOH) in tissues occurs, in part, from selective postabsorptive catabolism of non-α-TOH forms via the vitamin E-ω-oxidation pathway. We previously showed that global disruption of CYP4F14, the major but not the only mouse TOH-ω-hydroxylase, resulted in hyper-accumulation of γ-TOH in mice fed a soybean oil diet. In the current study, supplementation of Cyp4f14−/− mice with high levels of δ- and γ-TOH exacerbated tissue enrichment of these forms of vitamin E. However, at high dietary levels of TOH, mechanisms other than ω-hydroxylation dominate in resisting diet-induced accumulation of non-α-TOH. These include TOH metabolism via ω-1/ω-2 oxidation and fecal elimination of unmetabolized TOH. The ω-1 and ω-2 fecal metabolites of γ- and α-TOH were observed in human fecal material. Mice lacking all liver microsomal CYP activity due to disruption of cytochrome P450 reductase revealed the presence of extra-hepatic ω-, ω-1, and ω-2 TOH hydroxylase activities. TOH-ω-hydroxylase activity was exhibited by microsomes from mouse and human small intestine; murine activity was entirely due to CYP4F14. These findings shed new light on the role of TOH-ω-hydroxylase activity and other mechanisms in resisting diet-induced accumulation of tissue TOH and further characterize vitamin E metabolism in mice and humans.  相似文献   

15.
Metformin improves cardiac functional recovery after ischemia in rats.   总被引:3,自引:0,他引:3  
The biguanide, metformin, is widely used for the treatment of type 2 diabetes mellitus. In the recently published United Kingdom Prospective Diabetes Study (UKPDS), it was shown that the use of metformin was associated with a reduction of macrovascular complications compared to other blood glucose-lowering strategies. The present study was aimed at determining whether metformin has direct beneficial effects on the heart. We tested the effects of metformin on cardiac functional recovery after a mild ischemic incident (stunning) in our isolated, erythrocyte perfused, rat working-heart model. Three groups were tested: vehicle, 50 and 500 micromol/l metformin (total n = 6). In diabetic rats, a concentration of 50 microM has been shown to reduce the blood glucose concentration. Slight metformin-induced increases in coronary blood flow during normoxia (pre-ischemically) and during reperfusion (post-ischemically) were observed and compared to vehicle (p < 0.05). Both metformin concentrations significantly reduced cardiac functional loss induced by the 12-min global ischemic incident compared with vehicle (3.4 +/- 1.0 % and 3.5 +/- 0.6 % loss during metformin versus 10.7 +/- 0.8 % during vehicle, p < 0.001). This study clearly shows that metformin acutely improves cardiac function after a mild ischemic incident (stunning) in rats.  相似文献   

16.
The immune responses to diabetes in BB rats supplemented with vitamin A   总被引:2,自引:0,他引:2  
A substantial amount of evidence suggests that in type I diabetes, vitamin A and zinc status could be of concern because of their impaired metabolic availability. Because both vitamin A and zinc play important roles in the regulation of immune function, the present study was undertaken to examine the immune responses to vitamin A and zinc supplements in diabetic-prone Bio-Breed rats (BBdp), and if the supplements increase the incidence of diabetes. Weanling BBdp rats were fed a NIH-07 diet supplemented with vitamin A either alone or in combination with zinc up to 120 days of age. A greater percentage of rats developing diabetes was found in rats that had supplements of vitamin A and zinc (67%) than those on the basal diet (55%) or with vitamin A supplementation alone (50%). The B cells and macrophages were all markedly increased, whereas CD(4)(+) and CD(8)(+) T cells were decreased at the onset of diabetes. However, this immune status was not changed by vitamin A and zinc supplements. The plasma vitamin A levels were significantly decreased in the presence of diabetes and the vitamin A status did not improve when the rats were given vitamin A and zinc supplements. The Natural Killer cell cytotoxicity on a per-cell basis was significantly decreased in the presence of diabetes, irrespective of supplements with vitamin A and zinc. Overall, results indicated that vitamin A and immune status are both affected by type I diabetes; these effects, however, are not responsive to supplemental intakes of vitamin A either alone or in combination with zinc.  相似文献   

17.
Alpha-tocopherol level and fluidity were studied in the neuronal membrane of rat brain after exhaustive exercise. The order parameter, 5-doxyl-stearic acid (5-DS), which is utilized for assessing the fluidity of the lipid bilayer closer to the hydrophilic face of the membrane, decreased in the pons-medulla oblongata, and the motion parameter, 16-doxyl-stearic acid (16-DS) for the core of the lipid bilayer, decreased in the cortex, hippocampus, hypothalamus and striatum, whereas it increased in the cerebellum after exercise. The w/s ratio of n-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)-maleimido (maleimido-TEMPO) for the conformation of SH-protein also decreased in the hippocampus and midbrain after exercise. These changes were not observed in alpha-tocopheryl acetate supplemented rats after exercise. Although the levels of 5-DS, 16-DS and maleimido-TEMPO were affected by alpha-tocopheryl acetate in rat neuronal membranes, fluidity changes were reversible with exercise.  相似文献   

18.
The decreased oxidizability of plasma lipoproteins is related to the increased vitamin E intake and its association with a relatively lower incidence of coronary heart disease has been proposed. We investigated the effect of the in vivo vitamin E supplementation on the oxidizability of serum lipids in patients with ischemic heart disease and a moderate hypercholesterolemia. Thirty-two patients (16 males and 16 postmenopausal women) participated in this placebo-controlled, randomized trial. They were treated with 400 mg vitamin E/day for 6 weeks. The copper-induced serum lipid oxidizability ex vivo was assessed by measuring conjugated diene formation at 245 nm. We also measured vitamin E, malondialdehyde (MDA) and uric acid concentrations in the plasma. Because of observed significant differences in parameters of serum lipid oxidizability (lag time and maximal rate of oxidation), plasma alpha-tocopherol and MDA levels between male patients and postmenopausal women supplemented with vitamin E, the results were compared between both genders. Six weeks of vitamin E supplementation significantly increased plasma vitamin E levels (by 87 %) in male patients but in postmenopausal women only by 34 %. Concomitantly with increased plasma levels of vitamin E the decrease in plasma MDA levels was observed in male patients (decrease by 20 %; p=0.008), but in postmenopausal women the decrease did not attain statistical significance. Plasma uric acid levels were not apparently changed in placebo or vitamin E supplemented groups of patients. The changes in ex vivo serum lipid oxidizability after vitamin E, supplementation have shown a significantly prolonged lag time (by 11 %; p=0.048) and lowered rate of lipid oxidation (by 21 %; p=0.004) in male patients in comparison with postmenopausal women. Linear regression analysis revealed a significant correlation between plasma vitamin E levels and the lag time (r=0.77; p=0.03) and the maximal rate of serum lipid oxidation (r=-0.70; p=0.05) in male patients. However, in postmenopausal women the correlations were not significant. We conclude that 400 mg vitamin E/day supplementation in patients with ischemic heart disease and a moderate hypercholesterolemia influenced favorably ex vivo serum lipid oxidation of male patients when compared with postmenopausal women. The observed differences between both genders could be useful in the selection of the effective vitamin E doses in the prevention of coronary heart disease.  相似文献   

19.
This study was conducted to investigate effects of chlorogenic acid (CGA) supplementation on serum and hepatic metabolomes in rats. Rats received daily intragastric administration of either CGA (60 mg/kg body weight) or distilled water (control) for 4 weeks. Growth performance, serum biochemical profiles, and hepatic morphology were measured. Additionally, serum and liver tissue extracts were analyzed for metabolomes by high-resolution 1H nuclear magnetic resonance-based metabolomics and multivariate statistics. CGA did not affect rat growth performance, serum biochemical profiles, or hepatic morphology. However, supplementation with CGA decreased serum concentrations of lactate, pyruvate, succinate, citrate, β-hydroxybutyrate and acetoacetate, while increasing serum concentrations of glycine and hepatic concentrations of glutathione. These results suggest that CGA supplementation results in perturbation of energy and amino acid metabolism in rats. We suggest that glycine and glutathione in serum may be useful biomarkers for biological properties of CGA on nitrogen metabolism in vivo.  相似文献   

20.
The aim of the present study was to investigate the protective efficacy of alpha-lipoic acid (LA) on the cyclophosphamide (CP)-induced chromosomal aberrations (CA) and apoptosis in the bone marrow of rats. Male Wistar rats of 140+/-20 g were categorized into eight groups. Five groups were administered CP (40 mg/kg body weight, intraperitoneally) to induce toxicity; four of these groups received a single intraperitoneal injection of LA at a dose of either 100 or 200 mg/kg body weight, and either 30 or 60 min prior to CP administration. A vehicle-treated control group and LA control groups were also included. Twenty-four hours after CP treatment, the frequency of CA in bone marrow cells were significantly increased in comparison with the controls. The CP-induced CA were associated with significant increase in DNA damage in the bone marrow as evidenced by increased single strand breaks, whereas in rats treated with LA and CP, the frequency of CA and single strand breaks were significantly decreased in comparison to those given CP alone. CP administration distinctly triggered the apoptotic and necrotic cell death, and LA pretreatment affected cell death by decreasing the number of apoptotic and necrotic cells. The protective effect of LA was found to be stronger at a dose of 200 mg/kg body weight than 100 mg/kg body weight dosage, indicating the dose dependent protective effect of LA. However, the protection by LA was not dependent on the time intervals between LA and CP administration. The results of this study illustrate the protective effect of LA on the CA and apoptosis induced by CP in the erythropoietic system of rats.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号