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1.
Nitric oxide (NO) a free radical having both cytoprotective as well as tumor promoting agent is formed from l-arginine by converting it to l-citrulline via nitric oxide synthase enzymes. The reaction product of nitric oxide with superoxide generates potent oxidizing agent, peroxynitrite which is the main mediator of tissue and cellular injury. Peroxynitrite is reactive towards many biomolecules which includes amino acids, nucleic acid bases; metal containing compounds, etc. NO metabolites may play a key role in mediating many of the genotoxic/carcinogenic effects as DNA damage, protein or lipid modification, etc. The basic reactions of nitric oxide can be divided as direct effect of the radical where it alone plays a role in either damaging or protecting the cell milieu and an indirect effect in which the byproducts of nitric oxide formed by convergence of two independent radical generating pathways play the role in biological reactions which mainly involve oxidative and nitrosative stress. Nitric oxide is also capable of directly interacting with mitochondria through inhibition of respiration or by permeability transition. Reaction of nitric oxide with metal ions include its direct interaction with the metals or with oxo complexes thereby reducing them to lower valent state. Excessive production of nitric oxide can be studied by inhibiting the synthetic pathway of nitric oxide using both selective or specific nitric oxide synthase inhibitor or non-selective nitric oxide synthase inhibitor with respect to isoforms of nitric oxide.  相似文献   

2.
Nitric oxide (NO) derivative of l-arginine is an important signaling molecule that mediates a variety of essential physiological processes including vasodilation neurotransmission, and host cell defense. Many types of cells produce NO e.g., smooth muscle cell, endothelial cell, and leukocytes. Host defense functions are known for many bacterial and parasitic infections. In the present study we estimated the levels of serum NO in cases of salmonellosis and in controls. The nitric oxide was estimated by cadmium reduction method, Griess reaction. We observed that in controls the level of NO was (22 ± 2.06) μmol/l and in cases the level was (137.49 ± 29.84) μmol/l. The level of NO was significantly higher than controls (p < 0.001). The raised level of NO could be accounted for by host response to the infection. The host rapidly expresses iNOS, which in turn produces an excess amount of NO. Its cytotoxic effect is by its reactive nitrogen oxide derivative e.g., peroxynitrite. Apart from this it also has anti apoptotic functions. In future one can do follow up study of typhoid cases by bacterial culture.  相似文献   

3.
Diabetes mellitus (DM) is one of the most prevalent diseases in the world, which is strongly associated with liver dysfunction. Hyperglycemia, through an oxidative stress pathway, damages various tissues. Herbal medicine is a good candidate to ameliorate hyperglycemia and oxidative stress. In this study, the effects of aqueous Allium sativum (garlic) extract (AGE) on gene expression of inducible nitric oxide synthases (iNOS) and production of nitric oxide (NO) were evaluated in the liver tissue of diabetic rats. Four groups of rats contained normal control rats, garlic control rats (AGE), Streptozotocin (STZ) + nicotinamide-induced diabetic rats (DM), and diabetic rats treated with garlic (DM + AGE). Glucose levels and liver enzymes activities were determined by colorimetric assay in the serum. Gene expression of iNOS by real-time PCR, NO levels by Griess method, oxidative stress parameters by spectrophotometric method and histopathological examination by hematoxylin and eosin staining method were evaluated in the liver tissues. Glucose levels, activities of liver enzymes, oxidative stress markers, iNOS gene expression, and NO production increased significantly in diabetic rats in comparison with control rats, whereas after oral administration of garlic, these parameters decreased significantly, close to the normal levels. Hence, the beneficial effects of garlic on the liver injury of diabetes could be included in the hypoglycaemic and antioxidant properties of garlic via a decrease in gene expression of iNOS and subsequent NO production.  相似文献   

4.
Despite enormous research in the field of hypertension, its pathophysiology still remains largely unresolved and appears to be multifactorial. In the present communication, we have analyzed the status of nitric oxide (NO) in the patients with essential hypertension and age matched controls. We have found that the levels of NO are lowered in essential hypertension. The normalization of blood pressure by administration of antihypertensive therapy causes rise in the NO level indicating that perturbed NO status in essential hypertension is reversible. Addition of antioxidant to the antihypertensive drugs causes a further, though non significant, rise in the levels of NO, suggesting that antioxidants may be combined with antihypertensive drugs as adjunct in the management of essential hypertension.  相似文献   

5.
Crystal aggregation and retention are critical events for the formation of kidney stones. There is a close association between crystal development and free radical activity in vivo. In the present study 30 subjects presenting with urolithiasis were included. Serum levels of total lipid peroxides, nitric oxide (as nitrite), α-tocopherol, plasma ascorbic acid (vitamin C) and erythrocyte superoxide dismutase activity were measured. These findings were compared with 30 age matched control subjects irrespective of sex. Student's ‘t’ test was applied for statistical analysis. There was a significant increase in lipid peroxides (p<0.001), where as significant decrease in nitrite (p<0.01) and α-tocopherol (p<0.001) levels were observed. Plasma ascorbate (p>0.05) and erythrocyte superoxide dismutase activity (p>0.05) was also found to be decreased but the difference was not statistically significant which suggests that oxidative stress is evident in urolithiasis with depletion in antioxidant status where as decrease in nitric oxide may be less abetting in disease condition.  相似文献   

6.
Hemodynamic disorders of liver cirrhosis complicated with portal hypertension are associated with an increased angiogenesis in animal model of portal hypertension and cirrhosis which were linked to increased expression of vascular endothelial growth factor (VEGF) and nitric oxide (NO). The aim of study was to evaluate the serum concentration of VEGF and total nitric oxide (NO) in liver cirrhosis and the possible association with the degree of liver insufficiency. VEGF and NO were measured in serum of 64 patients with liver cirrhosis by ELISA and spectrophotometry respectively. The significant increase of serum VEGF was observed in liver cirrhosis compared to healthy individuals as well as serum NO (106.1 ± 66.7 vs. 41.5 ± 6 pg/mL, P < 0.05; 113.5 ± 65.8 vs. 20.8 ± 3.8 μmol/l, P< 0.001, respectively). Serum VEGF and NO showed significant associations with biochemical indices of liver function and with Child-pugh score where they were increased respectively to the degree of liver insufficiency. A significant association of raised serum NO in early stage of portal hypertension reflect its benefit in early expect of portal hypertension but, high serum VEGF in late stage may reflect its prognostic value in liver cirrhosis.  相似文献   

7.
The present study was undertaken to evaluate the levels of serum lipid peroxide, nitric oxide end poducts, erythrocytic superoxide dismutase activity and serum α 1-antitrypsin in smokers. Total 90 active cigarette smokers were subdivided into Group I (subjects with smoking habit of less than 10 cigarettes per day) and Group II (with smoking habit of more than 10 cigarettes per day). In both groups lipid peroxide and nitric oxide end products were significantly increased with significantly decrease in erythrocytic superoxide dismutase activity and serum α 1-antitrypsin as compared to controls. Our findings show enhanced oxidative stress and reduced α 1-antitrypsin in cigarette smokers. Further increase in number of cigarettes per day exacerbates the oxidative stress with decrease in α 1-antitrypsin.  相似文献   

8.
Defective sperm function is the most common cause of infertility. A prospective study was carried out to correlate the concentration of nitrite (the stable metabolite of nitric oxide) in seminal plasma with leukocytospermia, and sperm membrane integrity. Total Fifty-seven normozoospermic subjects with and without leukocytospermia visiting the Infertility clinic at KH and MRC, Karad, were included in the present study. Semen samples were checked for sperm concentration, total sperm count, sperm motility, seminal leukocyte concentration and sperm membrane integrity as Hypoosmotic Swelling Test. Similarly the concentration of nitrite in seminal plasma was measured by Griess reaction and total antioxidant power measured as ferric reducing ability of plasma. The concentration of nitrite in seminal plasma was found to be raised with significantly increased leukocyte concentration in semen. Also significantly lowered levels of total antioxidant power along with defective sperm function was observed. Our results suggest that supplementary treatment of antioxidants with antibiotic for leukocytospermic infertile male patients may improve the sperm membrane integrity.  相似文献   

9.
通过设备和工艺的改进,寻求成本低、产率高、比表面积大的工业化锑掺杂氧化锡ATO纳米导电粉体制备方法。即在络合能力强的复合有机酸溶液中加入纯度99.9%以上高纯锡和高纯锑化合物,再滴加硝酸和氨水,进行凝胶化反应和聚合反应,得到棕色透明液体,经过过滤、干燥、热分解和粉碎后,得到纯度达到99.0%以上、粒度小于100纳米、比表面积30m2/g的锑掺杂氧化锡ATO纳米导电粉体,工艺简单、生产周期短、成本低。  相似文献   

10.
Alpha-1-proteinase inhibitor activity was studied in presence of resting and activated polymorphonuclear leucocytes. Four different agonists; phorbol myristic acetate, N-formyl-methionyl-leucyl-phenylalanine, opsonised zymosan and arachidonic acid decreased the inhibitor activity by 23.3%, 20%, 12% and 16.6^ respectively. The inhibitor activity was protected by using various free radical scavengers. Catalase and superoxide dismutase both restored activity by about 18%, mannitol by 13% and sodium azide by 17.3%. The inhibitor activity was also protected significantly by pretreatment of polymorphs with L-Arg, a precursor of nitric oxide, before activation. L-Arg was also observed to suppress the generation of superoxide and hydroxyl radical appreciably. The nitric oxide synthase inhibitor, aminoguanidine drastically inhibited the nitrite release and reversed the protection offered by L-Arg to the inhibitor activity. Our results indicate a multifactorial nature of the inactivation process, the culprit species being superoxide, hydrogen peroxide, hydroxyl radical and hypohalides. Nitric oxide seems to scavenge the superoxide radical directly after its formation rather than inhibiting its generation by NADPH oxidase as was believed earlier.  相似文献   

11.
In the present study, the role of serum lipid peroxide and serum nitric oxide as oxidants and erythrocytic superoxide dismutase & serum vitamin E as antioxidants were determined in the 50 neonates with hypoxic ischaemic encephalopathy. (HIE) as against 25 healthy neonates as controls 50 patients of HIE were further divided into two groups i. e. mild and moderate HIE patients. All subjects were in the age group of 37–41 weeks of gestation. The levels of serum lipid peroxide, serum nitric oxide and erythrocytic superoxide dismutase were significantly elevated in both groups of neonates with HIE than those of controls (P<0.001), whereas serum vitamin E levels were significantly decreased in both groups of HIE patients than those of controls (P<0.001). A positive correlation was obtained between serum lipid peroxide and erythrocytic superoxide dismutase (r=+0.86). Alterations in the status of oxidants and antioxidants indicate role of free radicals in the development of HIE.  相似文献   

12.
Serum creatinine does not distinguish between various causes of graft dysfunction. Serial assay of proximal tubular enzymes N-Acetyl-D-glucosaminidase (NAG), Alanine aminopeptidase (AAP) and Gamma glutamyl transferase (GGT) in urine was done to assess their usefulness in distinguishing various causes of graft dysfunction. Daily serum creatinine and enzymuria were measured in 32 consecutive renal allograft recipients for first 15 postoperative days. Graft dysfunction was defined as >20% increase in serum creatinine and >100% increase in enzymuria over the baseline. The diagnosis of graft dysfunction was based upon clinical criteria, ultrasonography, cyclosporin trough level, allograft biopsy, response to anti-rejection therapy and alteration of cyclosporin dosage. Fifteen episodes of graft dysfunction were identified in 15 patients. The sensitivity and specificity of the enzymes (NAG, AAP and GGT) for predicting graft dysfunction were 87.5%, 86.9%, 88.5% and 98.2%, 98.2%, 97.9% respectively. There was a significant increase in enzymuria during acute tubular necrosis (ATN) and acute rejection episode compared to cyclosporin nephrotoxicity (p<0.01). Enzymuria assay provides a simple, reliable and noninvasive method to distinguish cyclosporin nephrotoxicity from acute tubular necrosis and acute rejection in renal allograft recipients.  相似文献   

13.
Generation of reactive oxygen species is an important factor in the development and maintenance of rheumatoid arthritis (RA) in humans. This study was undertaken to investigate interplay among oxidants, antioxidants and pathogenesis of Rheumatoid arthritis. Serum levels of lipid peroxides, nitric oxide, vitamin E and ratio of calcium/phosphorus in RA patients were determined and compared with normal healthy controls. Significant increases in lipid peroxides (p<0.001) and nitric oxide (p<0.001) levels were found in patients presenting with RA as compared to controls. Whereas significant decrease in vitamin E (P<0.001) and calcium/phosphorus ratio (p<0.001) were found in Rheumatoid arthritis patients as compared to controls. Positive correlation was found between lipid peroxides and nitric oxide as well as between vitamin E and calcium. While lipid peroxides and nitric oxide were correlated negatively with vitamin E. whereas negative correlation was observed between MDA and Calcium/Phosphorus ratio in patients with rheumatoid arthritis. Our findings suggest that there is a close association between bone loss and oxidative threat in patients presenting with Rheumatoid arthritis.  相似文献   

14.
This study was undertaken to evaluate the levels of plasma magnesium, lipid peroxides, nitric oxide end products, erythrocyte membrane lipid peroxides, erythrocyte reduced glutathione and erythrocyte superoxide dismutase activity in type-2 diabetes mellitus patients. 60 patients with type-2 diabetes mellitus and 30 healthy control subjects were included in this study. Among 60 type-2 diabetic patients, 30 patients were without complication and 30 patients were with various complications. Decreased levels of plasma magnesium, erythrocyte reduced glutathione and erythrocyte superoxide dismutase activity while increased levels of plasma lipid peroxides, nitric oxide end products and erythrocyte membrane lipid peroxides were observed in patients with type-2 diabetes mellitus. We propose that, under the shadow of hypomagnesaemia, there is excessive production of reactive oxygen species and reactive nitrogen species as reflected by elevated lipid peroxides and nitric oxide end products concomitant with dwindled antioxidants and suggest their association with late complications in type-2 diabetes mellitus.  相似文献   

15.
Psoriasis is a chronic inflammatory, proliferative skin disease characterized by pathological skin lesions due to various exogenous and endogenous factors. It is associated with a number of biochemical and immunological disturbances. Recently, it has been suggested that increased reactive oxygen species (ROS) production and compromised function of antioxidant system may be involved in the pathogenesis of this disease. In the present study, 90 psoriasis patients were selected. Disease severity was assessed by psoriasis area severity index score and grouped as mild, moderate and severe (each group consists of 30 subjects) and compared with 30 healthy controls. Serum levels of malondialdehyde, nitric oxide end products and the activities of antioxidant enzymes such as erythrocyte-superoxide dismutase, catalase and total antioxidant status were investigated in these groups/subjects. As compared to controls, we found severitywise significantly increased serum malondialdehyde, nitric oxide end products with decrease in erythrocyte-superoxide dismutase activity, catalase activity and total antioxidant status in patients with psoriasis suggesting worsening of the disease. It seems to be linked with the enhancement of Reactive Oxygen Species production and decreased antioxidant potential in psoriasis.  相似文献   

16.
The effect of Emblica officinalis fruit extract (EFE) against alcohol-induced hepatic damage in rats was investigated in the present study. In vitro studies showed that EFE possesses antioxidant as well nitric oxide (NO) scavenging activity. In vivo administration of alcohol (5 g/kg b.wt/day) for 60 days resulted increased liver lipid peroxidation, protein carbonyls, nitrite plus nitrate levels. Alcohol administration also significantly lowers the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and reduced glutathione as compared with control rats. Administration of EFE (250 mg/kg body weight) to alcoholic rats significantly brought the plasma enzymes towards near normal level and also significantly reduced the levels of lipid peroxidation, protein carbonyls and restored the enzymic and non-enzymatic antioxidants level. This observation was supplemented by histopathological examination in liver. Our data indicate that the tannoid, flavonoid and NO scavenging compounds present in EFE may offer protection against free radical mediated oxidative stress in rat hepatocytes of animals with alcohol-induced liver injury.  相似文献   

17.
New findings on organization of blood cell cytoskeleton represent an exciting aspect of modem cell biology and hematology, which is an interesting investigation to study diabetes. The present study was undertaken in 150 subjects. Out of these, 30 subjects were controls (Group I) and 30 were type-2 diabetics without any complication (Group II), while remaining 90 subjects were type-2 diabetics with complication (Group III). We determined erythrocyte spectrin and hemoglobin glycosylation and also estimated plasma lipid peroxide, nitric oxide and erythrocyte glutathione peroxidase activity to assess the status of oxidative stress. There was a significant increase in spectrin (P<0.001) and hemoglobin (P<0.001) glycosylation in Group II and III as compared to Group I and spectrin glycosylation was nearly three times more as compared to hemoglobin, whereas plasma levels of lipid peroxide (P<0.001) as well as nitric oxide (P<0.001) were found to be significantly increased and GPx activity (P<0.001) was significantly decreased in Group II and III as compared to Group I. However, it was also observed that spectrin (P>0.05) and hemoglobin (P>0.05) glycosylation was not significantly different in Group II and III. In contrast, there was significant rise in lipid peroxide (P<0.001), nitric oxide (P<0.001) and fall in GPx activity (P<0.001) in Group III when compared to Group II. Increased erythrocyte protein glycosylation and oxidative stress is clearly evident from our study. However, to understand the exact interplay between these two mechanisms, further studies are required.  相似文献   

18.
Liver transplantation is an accepted therapy for chronic liver disease patients. These patients generally have low levels of fat soluble vitamins, which have important antioxidant roles. Therefore, this study was undertaken to investigate whether such patients had evidence of antioxidant depletion and increased lipid peroxidation before transplant and whether the subsequent ischemia and reperfusion encountered during liver transplantation have any effect on antioxidant levels and lipid peroxidation. We assessed plasma total antioxidant capacity and serum lipid peroxide in 12 patients undergoing liver transplantation and equal numbers of healthy subjects. We found that before reperfusion, antioxidant levels were significantly decreased along with significantly elevated lipid peroxidation levels as compared with healthy controls (P<0.001). On reperfusion of the liver graft, further declined values of total antioxidant accompanied with highly elevated lipid peroxidation were seen than those of pre-reperfusion samples (P<0.001). This data shows that patients undergoing liver transplant have lowered antioxidant defenses and evidence of free radical damage, which compound the additional insult of reperfusion injury. Therefore antioxidant therapy in these patients before transplantation may ameliorate the effects of reperfusion.  相似文献   

19.
Cellular transplantation is a promising technology with great clinical potential in regenerative medicine and disease management. However, effective control over patient immunological response is essential. The encapsulation of cells within hydrogel microspheres is an increasingly prevalent method for the protection of cellular grafts from immune rejection. Microfluidic “chip” reactors present elegant solutions to several capsule generation issues, including the requirement for intercapsule uniformity, high reproducibility, and sterile, good manufacturing practice compliance. This study presents a novel method for the on-chip production of stable, highly monodisperse alginate microspheres and demonstrates its utility in the encapsulation of an immortalized human-derived cell line. Four populations of immortalized human embryonic kidney cells (HEK293) were encapsulated on chip within monodisperse alginate capsules. Cell viability measurements were recorded for each of the four encapsulated populations for 90 days.  相似文献   

20.
Oxidative stress in Parkinson’s disease   总被引：1，自引：0，他引：1  
Oxidative stress contributes to the cascade, leading to dopamine cell degeneration in Parkinson’s disease. However, oxidative stress is intimately linked to other components of the degenerative process, such as mitochondrial dysfunction, excitotoxicity, nitric oxide toxicity and inflammation. It is therefore difficult to determine whether oxidative stress leads to or is a consequence of, these events. Oxidative stress was assessed by estimating lipid peroxidation product in the form of thiobarbituric acid reactive substances, nitric oxide in the form of nitrite & nitrate. Enzymatic antioxidants in the form of superoxide dismutase, glutathione peroxidase, catalase, ceruloplasmin and non enzymatic antioxidant vitamins e.g. vitamin E and C in either serum or plasma or erythrocyte in 40 patients of Parkinson’s disease in the age group 40–80 years. Trace elements e.g. copper, zinc and selenium were also estimated. Plasma thiobarbituric acid reactive substances and nitric oxide levels were Significantly high but superoxide dismutase, glutathione peroxidase, catalase, ceruloplasmin, vitamin-E, vitamin-C, copper, zinc and selenium levels were significantly low in Parkinson’s disease when compared with control subjects. Present study showed that elevated oxidative stress may be playing a role in dopaminergic neuronal loss in substentia nigra pars compacta and involved in pathogenesis of the Parkinson’s disease.  相似文献   

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