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1.
Peroxidative damage to DNA initiated by methyl ethyl ketone peroxide, a potent initiator of lipid peroxidation, and protection against this damage by vitamin E were studied in rats. Groups of rats were fed a casein-based diet that contained 10% tocopherol-stripped corn oil and either 0, 3, 5, or 10 IU of DL-alpha-tocopherol acetate/kg; the groups were named 0, 3, 5, or 10, respectively. DNA isolated from the brains of these rats was analyzed for template activity, bound tryptophan, and malondialdehyde-type DNA-protein and interstrand DNA crosslinks. The DNA of groups 5 and 10 had significantly higher template activity, less bound tryptophan, and fewer crosslinks than that of groups 3 and 5, respectively. The DNA of group 3 had significantly fewer interstrand DNA crosslinks than that of group 0, and the most significant differences were between groups 3 and 5. Loss of template activity correlated best with interstrand DNA crosslinks, and bound tryptophan correlated best with DNA-protein crosslinks. Electrophoresis of the RNA transcribed from the isolated DNA showed that a significantly higher percentage of longer RNA was made from the DNA of groups 5 and 10 than from that of group 0. The apparent molecular weight of the DNA of group 0 was less than that of group 10 and was more heterogeneous, which suggests fragmentation and/or crosslinking. The DNA from group 10 had maximum observed template activity; therefore, 10 IU of vitamin E/kg of diet appeared to be adequate to protect brain DNA against the damage measured in this study.  相似文献   

2.
1,3-Propanediol (PAD) was fed to rats for 15 weeks, and its effects on hepatic and testicular DNA were studied. The control rats were fed a casein-based diet that contained 10% tocopherol-stripped corn oil with 30 IU of d,l-α-tocopherol acetate/kg; the experimental rats were fed the same diet with 500 ppm of PAD. Homogenates prepared from the livers of each group of rats converted 1,3-propanediol to malondialdehyde (MDA) with equal efficacy, but homogenates of testes did not catalyze this conversion. After 10–15 weeks of feeding the diets, the hepatic DNA of the rats fed PAD had less template activity, more bound tryptophan and more DNA-protein and interstrand DNA cross-links than that of the control rats. As measured by template activity and bound tryptophan, testicular DNA of the experimental rats was not different from that of the control rats; however, there was slightly more cross-linking in the testicular DNA of experimental rats than in that of control rats. Testes of the experimental rats contained more lipid-soluble fluorophores than did those of the control rats. The results are consistent with the conclusion that PAD was converted to MDA in vivo and that MDA is the reactive species that caused the observed biological damage.  相似文献   

3.
Angiotensin-converting enzyme (ACE) as a part of the renin angiotensin system (RES) regulates blood pressure and fluid and electrolyte homeostasis, and the enzyme is considered to have a function in reproduction. Reduced enzyme activities have been observed in atrophied testes as a results of zinc and pituitary deficiencies. Vitamin A deficiency causes atrophy of testes. The present study was conducted on three groups of male, 3-wk-old, Wistar rats. After 54 d of the experimental period, testicular weights of the vitamin A-deficient rats (Agroup, allowed free access to vitamin Adeficient diet) was significantly lower than its pair-fed, PF (given restricted amount control diet) and A+ (allowed free access to control diet) groups. Zinc concentrations and both soluble and particulate ACE activities in the testes of vitamin A-deficient rats (Agroup) were significantly lower than the other two groups. No significant differences were observed regarding zinc concentration, particulate ACE, and total ACE activities in the testes of PF and A+ groups. Vitamin A deficiency did not significantly affect the enzyme activity in the lung. From the observations of the present study, we speculate that testicular atrophy in vitamin A deficiency may have resulted from lower zinc concentration and decreased ACE activity in that organ.  相似文献   

4.
Complex interrelationships exist between hyperlipidemia and the progression of renal injury. The aim of this study was to evaluate the impact of high plasma cholesterol and triglyceride levels on renal structure and the effects of atorvastatin on progression-regression of renal injury. One-hundred chickens were divided into five groups: Group A: Standard diet (SD) for 6 months; Group B: Hyperlipidemic diet (HD) for 6 months; Group C: HD for three months and SD during the next 3 months; Group D: HD for 3 months and SD during the next 3 months, when they received oral atorvastatin (3 mg/kg/d); Group E: HD for the whole 6 months, and atorvastatin (3 mg/kg/d) during the last 3 months. Increased alpha-actine immunostaining was found in glomeruli of groups B and C. An important decrease of immunostaining was observed in glomeruli of atorvastatin treated groups. Group D showed the lowest value for presence of lipids, and significant differences were found with respect to the rest of the groups. The glomeruli of group B presented the highest damage grades and those of group D showed the lowest grades and presented significant differences from the rest of the groups. The combination of atorvastatin therapy and proper diet proved to be effective in promoting renal disease regression. However, the study of several parameters indicates that neither only diet nor atorvastatin in the progression group resulted completely effective in decreasing the progression of the disease.  相似文献   

5.
《Free radical research》2013,47(5):299-309
Copper, zinc superoxide dismutase (Cu, ZnSOD) and manganese superoxide dismutase (MnSOD) activities were measured in mouse large intestinal mucosa during dimethylhydrazine (DMH) carcinogenesis. Mice were divided into five groups. Group A was subcutaneously injected with DMH (20mg/kg) weekly and fed with a diet containing 0.2% cholic acid (C) and 0.8% indole (I). Group B was injected with DMH and given indole feeding. Group C was treated with DMH injection and cholic acid feeding. Group D was given DMH injection alone. Group E was an age-matched control group given 0.9% NaCl injection. The experiment last 21 weeks. The Cu, ZnSOD activity of intestinal mucosa in group A animals began to increase significantly at the 7th week of the experiment. In groups B, C and D, however, this enzyme was not elevated statistically until the 16th week, and then each of these groups kept an increased Cu, ZnSOD level the rest of the experimental period. MnSOD activity was elevated statistically in group C animals at the 7th week. The enzyme activity in group A and D animals increased at the 9th week, but the enzyme activity did not increase statistically until the 11th week in group B. After the 16th week of the experiment the increased activity of MnSOD in all experimental groups returned to the level of the control group. Large intestinal cancer tissues had increased Cu, ZnSOD activity and decreased MnSOD activity.  相似文献   

6.
Copper, zinc superoxide dismutase (Cu, ZnSOD) and manganese superoxide dismutase (MnSOD) activities were measured in mouse large intestinal mucosa during dimethylhydrazine (DMH) carcinogenesis. Mice were divided into five groups. Group A was subcutaneously injected with DMH (20mg/kg) weekly and fed with a diet containing 0.2% cholic acid (C) and 0.8% indole (I). Group B was injected with DMH and given indole feeding. Group C was treated with DMH injection and cholic acid feeding. Group D was given DMH injection alone. Group E was an age-matched control group given 0.9% NaCl injection. The experiment last 21 weeks. The Cu, ZnSOD activity of intestinal mucosa in group A animals began to increase significantly at the 7th week of the experiment. In groups B, C and D, however, this enzyme was not elevated statistically until the 16th week, and then each of these groups kept an increased Cu, ZnSOD level the rest of the experimental period. MnSOD activity was elevated statistically in group C animals at the 7th week. The enzyme activity in group A and D animals increased at the 9th week, but the enzyme activity did not increase statistically until the 11th week in group B. After the 16th week of the experiment the increased activity of MnSOD in all experimental groups returned to the level of the control group. Large intestinal cancer tissues had increased Cu, ZnSOD activity and decreased MnSOD activity.  相似文献   

7.
RNA polymerases A and B from Physarum were more active on denatured homologous, calf thymus, or phage DNA than on the corresponding native templates. We obtained distinct patterns of template activities for various single- and double-stranded synthetic homopolymers and alternating copolymers. Some templates were copied asymmetrically. All dC-rich structures were highly active templates. Poly(dA) was efficiently transcribed only in combination with oligo(dT), not with poly(dT). Differential activities of enzymes A and B on several synthetic templates and phage DNA suggest different requirements for the RNA synthesis by the two RNA polymerases from Physarum.  相似文献   

8.
水母雪莲细胞培养物调血脂作用的初步研究   总被引:4,自引:0,他引:4  
为研究水母雪莲细胞培养物对高脂大鼠的调血脂作用,将雄性SD大鼠分为4组:正常对照组(A组)、高脂模型组(B组)、高剂量组(C组)和低剂量组(D组)。A组喂基础饲料,B组喂高脂饲料,C组喂高脂饲料的同时饲以大剂量水母雪莲细胞培养物,D组喂高脂饲料的同时饲以小剂量水母雪莲细胞培养物。给药1/d,3周后采血,测定血脂水平及肝肾功能。C组较B组各项血脂指标均有改善,各组间肝肾功能未见显性差异。初步研究表明,水母雪莲细胞培养物对高脂大鼠具有调血脂的作用。本实验用药剂量安全。  相似文献   

9.
目的探讨睾酮对雄兔血高敏C反应蛋白(hs-CRP)、基质金属蛋白酶-9(MMP-9)、血红素氧化酶-1(HO-1)、脂联素(APN)和动脉粥样硬化斑块稳定性的影响。方法将66只雄性新西兰纯种兔随机分为4组,其中正常对照组10只(A组)、喂以普通饲料;假去势+球囊损伤颈动脉组16只(B组)、去势+球囊损伤颈动脉+生理剂量睾酮(6mg/(kg.2周))肌注组16只(C组)、去势+球囊损伤颈动脉+生理盐水肌注组24只(D组)均喂以高脂饲料。在实验第8周随机抽取处死部分动物,观察颈动脉病变的形态特征,抽血测睾酮、hs-CRP、MMP-9、HO-1、APN水平。结果D组兔血睾酮水平显著降低;B,C组较D组兔血hs-CRP、MMP-9水平显著降低,HO-1、APN水平显著升高;且B,C组较D组兔动脉粥样斑块的面积和内-中膜厚度(IMT)显著减小,斑块纤维帽增厚、胶原含量明显增加。结论生理剂量睾酮可以影响雄兔血hs-CRP、MMP-9、HO-1、APN水平,并能调节动脉粥样硬化斑块进展与斑块的稳定性。  相似文献   

10.
Oxidative stress occurs during maximal exercise, perhaps as a result of increased consumption of oxygen. Vitamins C and E can overcome the effects of antioxidants in exercise. We investigated the effects of supplementation with a combination of vitamin C and E (VCE) on blood lipid peroxidation (LP) and antioxidant levels following maximal training in basketball players. Blood samples were taken from 14 players (group A) and divided into two subgroups namely maximal training (group B) and maximal training plus VCE groups (group C). Group B maximally exercised for 35 days. VCE was supplemented to group C for 35 days and blood samples were taken from group B and C. Plasma and hemolyzed erythrocyte samples were obtained from the players. Erythrocyte glutathione peroxidase (GSH‐Px) activity and plasma vitamin E concentration were lower in group B than in group A, whereas plasma and erythrocyte LP levels were higher in group B than in group A. Plasma vitamin A, vitamin E, erythrocyte GSH‐Px, and reduced glutathione (GSH) values were higher in group C than in groups A and B although LP levels in plasma and erythrocytes were lower in group C than in group A and B. β‐Carotene values did not change in the three groups. In conclusion, VCE supplementation in maximal exercising basketball players may strengthen the antioxidant defense system by decreasing reactive oxygen species (ROS). Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

11.
Temperature-sensitive (ts) mutants of Newcastle disease virus have been isolated and characterized genetically (complementation), biochemically (RNA synthesis) and biologically (fusion from within and hemadsorption). Fifteen of these mutants have been divided into five complementation groups. Groups A (five mutants) and E (one mutant) are ts for RNA synthesis (RNA-) as well as for the other functions. Group B contains four RNA+ mutants of which one is ts for fusion, one for hemadsorption and two for neither function. Group C contains one RNA+ mutant which is a poor cell fuser. Group D contains two RNA+ mutants which are ts for fusion. In addition, two noncomplementing mutants (group BC) fail to complement both group B and group C mutants while exhibiting complementation with mutants in groups A, D, and E.  相似文献   

12.
This study investigated effects of dietary supplementation with vitamin C, vitamin E on performance, biochemical parameters, and oxidative stress induced by copper toxicity in broilers. A total of 240, 1-day-old, broilers were assigned to eight groups with three replicates of 10 chicks each. The groups were fed on the following diets: control (basal diet), vitamin C (250 mg/kg diet), vitamin E (250 mg/kg diet), vitamin C + vitamin E (250 mg/kg?+?250 mg/kg diet), and copper (300 mg/kg diet) alone or in combination with the corresponding vitamins. At the 6th week, the body weights of broilers were decreased in copper, copper + vitamin E, and copper + vitamin C + vitamin E groups compared to control. The feed conversion ratio was poor in copper group. Plasma aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase activities, iron, copper concentrations, and erythrocyte malondialdehyde were increased; plasma vitamin A and C concentrations and erythrocyte superoxide dismutase were decreased in copper group compared to control. Glutathione peroxidase, vitamin C, and iron levels were increased; aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and copper levels were decreased in copper + vitamin C group, while superoxide dismutase, glutathione peroxidase, and vitamin E concentrations were increased; aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were decreased in copper with vitamin E group compared to copper group. The vitamin C concentrations were increased; copper, uric acid, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and malondialdehyde were decreased in copper + vitamin C + vitamin E group compared to copper group. To conclude, copper caused oxidative stress in broilers. The combination of vitamin C and vitamin E addition might alleviate the harmful effects of copper as demonstrated by decreased lipid peroxidation and hepatic enzymes.  相似文献   

13.
In the present study, polysaccharides were extracted from the Lycium chinensis (LCP). Rats were divided into four groups. Two groups (Groups A) were maintained on the basal diet, whereas the remaining three groups (Groups B, C and D) had free access to the basal diet and were orally fed with LCP at 200 mg/kg b.w. for Group B, 400 mg/kg b.w. for Group C and 600 mg/kg b.w. for Group D, respectively. Following 4 weeks of this dietary regimen, hepatocarcinogenesis was initiated in all animals by a single intraperitoneal DENA (Sigma-Aldrich, St. Louis, MO, USA) injection at a dose of 200 mg/kg body weight (mixed with peanut oil). Results still showed that L. chinensis polysaccharides (LCP) increased spleen, thymus indexs, antioxidant enzymes activities and decreased oxidative injury. In addition, LCP still significantly affect VEGF and Cyclin D1 proteins expression in liver cancer rats. It can be concluded that LCP exhibited remarkable protective effects against diethylnitrosamine (DEN)-induced oxidative hepatic injury in liver cancer rats.  相似文献   

14.
目的:通过观察Exendin-4对糖尿病大鼠脑缺血再灌注后脑梗死体积百分比及脑组织中金属基质蛋白酶-9及基质金属蛋白酶抑制剂-1的变化,探讨Exendin-4对糖尿病大鼠脑缺血再灌注损伤的保护作用机制。方法:选用SD大鼠,给予链脲佐菌素(streptozocin,STZ)建立糖尿病大鼠模型后,随机分为A组:糖尿病对照组(n=6);B组:模型组(n=6);C组:Exendin-4低剂量组(n=6);D组:Exendin-4中剂量组(n=6);E组:Exendin-4高剂量组(n=6)。常规喂养6周后,A组给予假手术处理,B、C、D及E组采用线栓法制作大鼠大脑中动脉缺血90 min再灌注模型,24 h后处死大鼠取脑组织,采用2,3,5一氯化三苯四唑(2,3,5-triphenyltetrazolium chloride,TTC)染色测算脑梗死体积百分比;同时分别采用Western Blot法及RT-PCR测量脑组织中的MMP-9及TIMP-1表达量。结果:脑缺血再灌注能致脑组织中MMP-9及TIMP-1表达量增高,各组与A组比较,有显著差异(P<0.05);给予Exendin-4处理后脑组织中MMP-9及TIMP-1表达增高程度及脑梗死体积百分比明显降低,与B组比较有显著差异(P<0.05)。结论:Exendin-4对糖尿病大鼠脑缺血再灌注损伤有保护作用,其机制可能与抑制MMP-9及TIMP-1的表达有关。  相似文献   

15.
The aim of this study was to evaluate the utilization of a standard treatment with diminazene aceturate against the infection caused by Trypanosoma evansi, associated to sodium selenite and vitamin E. In vitro tests showed trypanocidal effect related to the treatment with diminazene aceturate and sodium selenite, but vitamin E had no harmful effect on the trypanosomes. In vivo experiments utilized a total of 72 adult outbreed females rats, separated into 9 groups (A, B, C, D, E, F, G, H and I), 8 animals each. Group A was the uninfected group; groups B to I were infected with 0.2 mL of blood containing 106 trypanosomes. Parasitemia was estimated daily by microscopic examination of blood smears. Group B served as positive control; group C was treated with diminazene aceturate; group D with sodium selenite; group E with vitamin E; group F received an association of diminazene aceturate and sodium selenite; group G received an association of diminazene aceturate and vitamin E; group H received an association of diminazene aceturate, sodium selenite and vitamin E, and group I received an association of sodium selenite and vitamin E. Diminazene aceturate was administrated in a single dose on the 3rd day post infection (PI). Sodium selenite and vitamin E were administered at the 3rd and 23rd day PI. In vivo tests showed increase of longevity in groups treated with diminazene aceturate associated with sodium selenite (groups F and H). No difference was found between groups C and E, thus the vitamin E did not increase the efficacy of treatment against T. evansi when associated to diminazene aceturate. The curative efficacy of treatments was 37.5, 87.7, 37.7 and 75% to the groups C, F, G and H, respectively. Other treatments showed no efficacy. The sodium selenite when combined with chemotherapy may represent an alternative in the treatment of trypanosomosis.  相似文献   

16.
The aim of the study was to get further experimental data on the anticariogenic effect of sodium fluoride (NaF) when administered in milk or water. Thirty six weanling Osborne-Mendel rats were divided into two experimental groups (A, B) of 12 rats each and two control groups (C, D) of six rats each. During the experimental period of four weeks all animals were superinfected with Strep. mutans (NCTC 10449), kept in an automatic feeding machine and given a cariogenic diet (MIT 301). Group A received sodium fluoride (NaF) in water (15 ppm) and group B in ultra high temperature treated milk. Groups C and D respectively received plain milk and distilled water. Group A did not show significantly lower caries reduction compared with the control groups. Group B had significantly the lowest caries scores compared with all other groups. Scores in group C (plain milk) were lower than those in groups D (plain water). The results suggest that the anticariogenic effect of NaF is more pronounced when the vehicle is milk instead of water.  相似文献   

17.
1. Aflatoxin B(1), administered in vivo, inhibits the incorporation of [(14)C]orotic acid in vivo into rat liver nuclei, and also inhibits both Mg(2+)- and Mn(2+)-dependent RNA polymerase activities in nuclei assayed in vitro. 2. Aflatoxin B(1) inhibits the cortisol-induced increase in incorporation of [(14)C]leucine in vivo, but does not affect the control value of this activity. 3. Aflatoxin B(1) administered in vivo inhibits the increase in nuclear Mg(2+)-dependent RNA polymerase activity, assayed in vitro, which results from the treatment with cortisol. 4. Adrenalectomy causes a decrease in Mg(2+)-dependent RNA polymerase activity. The effect on this enzymic activity of adrenalectomy plus treatment with aflatoxin B(1) is no greater than that of treatment with aflatoxin B(1) alone. 5. These results suggest that the inhibition of cortisol-stimulated biochemical pathways by aflatoxin B(1) is due to an inhibition of cortisol-stimulated RNA synthesis. 6. The cytoplasmic action of aflatoxin is thought to be due to a competition for receptor sites on the endoplasmic reticulum between steroid hormones and aflatoxin B(1). No evidence was obtained for a similar competition for nuclear receptor sites between [(3)H]cortisol and aflatoxin B(1). 7. No differences were observed between the activities of RNA polymerase preparations solubilized from control or aflatoxin-inhibited nuclei. 8. No differences in ;melting' profiles were observed between DNA and chromatin preparations isolated from control nuclei or from aflatoxin-inhibited nuclei. 9. It is suggested that aflatoxin B(1) exerts its effect on RNA polymerase by decreasing the template capacity of the chromatin and that the aflatoxin ;target' area of the chromatin includes that region which is stimulated by cortisol. This process, however, does not involve inhibiting the movement of cortisol from the outside of the hepatic cell to the nuclear chromatin.  相似文献   

18.
The present study was aimed to investigate the mechanisms by which vitamin A plays a role in maintaining the efficiency of gastric mucosal barrier. Particularly, we measured electrical parameters and the RNA/DNA ratio of gastric mucosa isolated in vitro from the stomach of rats in which vitamin A-deficiency was induced by means of a vitamin A-free diet and then abolished by means of a massive vitamin A supplementation. Pair-fed vitamin A-nondepleted rats and normal rats fed ad libitum on a standard diet served as controls. Vitamin A status was assayed for each group of rats by measuring the hepatic content of vitamin A. We found that in gastric mucosa vitamin A-deficiency induced: 1) a decrease in both transmucosal potential difference and short-circuit current; 2) an increase in transmucosal electrical resistance; 3) a decrease in RNA content resulting in a decreased RNA/DNA ratio. Abolishment of vitamin A-deficiency restored both electrical parameters and RNA content of rat gastric mucosa. Our results stress the role of vitamin A in maintaining the efficiency of the gastric mucosal barrier. Vitamin A seems to act by stabilizing gastric electrical parameters and by controlling the protein synthesis/turnover in the surface gastric mucosal cells.  相似文献   

19.
Diabetes mellitus is associated with diabetic impairment of testicular function, ultimately leading to reduced fertility. Its etiology may involve oxidative damage by reactive oxygen substances, and protection against this damage can be offered by antioxidant supplementation. The aim of this study was to investigate the effects of intraperitoneal administration of vitamin C and E, selenium (Se), and vitamin E plus Se (COM) on concentrations of lipid peroxide (as malondialdehyde; MDA), reduced glutathione (GSH), and vitamin E concentrations and glutathione peroxidase (GSH-Px) activity in the testes of rats with diabetes induced by streptozotocin (STZ). Sixty groups were used (10 animals each) and these animals were initially allocated to two groups: control group and diabetic group. The diabetic group was subdivided into five groups as follows: diabetic control (DC), vitamin E, Se, COM, and vitamin C. Animals in the DC group and vitamin C, vitamin E, Se, and COM groups were made diabetic by the injection of STZ on 4 d after an injection of vitamins C and E, Se, and COM. Those vitamins and Se were also administered for 21 consecutive days. The MDA, vitamin E, GSH levels, and GSH-Px activities in testes were determined. Although the vitamin E concentration was higher in the control than in the DC group, the MDA levels were found to be lower in the control than in the DC group. The MDA levels in the testes samples of vitamin C, vitamin E, Se, and COM groups were lower than the DC group. However, GSH-Px activity and GSH levels in the testes were not significantly different between the control and DC groups. Vitamin E concentrations in the vitamin C, vitamin E, Se, and COM groups and GSH levels and GSH-Px activities in the Se, COM, and vitamin C groups were higher than either the control or DC group. The results indicate that reactive oxygen substances may be involved in possible testicular complications in diabetes of rats. Administration of vitamins C and E and Se reduced the testicular lipid peroxidation; these vitamins and Se had significant protective effects on testes of rats against oxidative damage in diabetes.  相似文献   

20.
Formation of hybrids between viral deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) was used to detect virus-specific RNA in the nuclei and polyribosomes of transformed and tumor cells induced by "highly" oncogenic human adenovirus (Ad) types 12, 18, and 31. The presence of virus-specific RNA in the cell nucleus, and the inhibitory effect of actinomycin D on its synthesis, suggest that adenovirus-specific RNA is transcribed from a DNA template in the nucleus. Ad 12, 18, and 31 virus-specific RNA did not hybridize significantly with the DNA of the "weakly" oncogenic adenovirus group (Ad 3, 7, 11, 14, 16, and 21) or with that of nononcogenic Ad 2 and 4. Labeled RNA from Ad 12, 18, and 31 tumor cells hybridized with heterologous Ad 12, 18, and 31 DNA 30 to 60% as efficiently as with homologous DNA. Thus, common viral genes are transcribed in tumor cells induced by Ad 12, 18, and 31.  相似文献   

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