method used

It is particularly important, when analyzing biological material, for the measurement procedure to be specific to the analyte and not to suffer interference by the matrix effect. Tissue fraction studies also require rapid and accurate methods to estimate the concentration of protein in solutions as well as many measurement methods used in medical laboratories. The design of this study is based on a comparison of the Lowry and the bicinchoninic acid (BCA) methods for the measurement of the total protein concentrations of rat liver subcellular fractions. In our experiment, subcellular fractions enriched in peroxisomes (POs) obtained by differential centrifugation were then further separated by means of density gradient centrifugation. We performed the protein measurement assays on all fractions obtained during the purification steps. The protein contents of the fractions obtained were determined by the two methods. The method comparison statistics were performed by linear Deming regression analysis and Altman and Bland bias plot. The regression equation was unacceptable, indicating that the last three fractions separated by means of Nycodenz discontinuous density gradient centrifugation gave remarkably divergent results. For the Lowry method, the Nycodenz effect could not be eliminated with the use of interference blank. In addition to Nycodenz, the potentially interfering compound used in the isolation procedure as isolation medium was 3-(morpholino)propane sulfonic acid (MOPS). In decreased concentrations of MOPS (10 mM), interference blank should be used for correct measurement with Lowry, but in practical use 10 mM does not provide buffering potency. In the BCA method, interference blank correction seemed to eliminate the measurement error in all concentrations of Nycodenz. There was no MOPS effect on the BCA measurement assay. Referring to deviations as sample-inherent matrix effects, we concluded that not only one, but more measurement methods should be used in order to make a correct protein measurement

Sex differences in nitrite/nitrate levels and antioxidant defense in rat brain

WOS: A1997WU31300016PubMed ID: 9141057THIS Study assessed sex differences in stable metabolites of nitric oxide and major enzymes involved in antioxidant defense in various regions of rat brain. Nitrite/nitrate nitrate levels and activities of superoxide dismutase and catalase were determined in cortex, hippocampus, corpus striatum, midbrain and cerebellum of adult male and female Sprague-Dawley rats. Nitrite/nitrate levels were significantly higher in the cortex and the hippocampus of male than female rats, while catalase activity was higher in the cortex of females than in males. These sex differences may have significant effects on brain function in health and disease

Possible supportive effects of co-dergocrine mesylate on antioxidant enzyme systems in aged rat brain

WOS: 000071526300003PubMed ID: 9452935Free radical damage is implicated in the course of many diseases, including age-related dementias. Oxidative deamination of primary monoamino oxidase (MAO) produces NH3 and H2O2 with established or potential toxicity. MAO activity is increased in aged rat brain and significantly lowered by chronic hydergine (codergocrine mesylate, Sandoz) treatment. The aim of this study was to investigate the effects of hydergine on enzymatic antioxidant defense systems. Hydergine or vehicle was administered systemically to young (3 months) and aged (18 months) Sprague-Dawley rats for 20 days and 24 h after the termination of the treatment, superoxide dismutase (SOD) and catalase (CAT) activities were determined in some brain regions. SOD and CAT activities were higher in the aged animals and were further increased with hydergine treatment. The increase in SOD levels caused by hydergine treatment in the aged animals were the most prominent in the hippocampus and in the corpus striatum. There was no region-specific effect of hydergine treatment on CAT levels in aged animals. The possible causal relationship between increased MAO activity, a generator of free radicals, and increased antioxidant defense in aging brain require further investigation. Decreasing MAO levels and supporting the antioxidant enzymes may underlie the efficacy of hydergine in the treatment of age related cognitive decline. (C) 1998 Elsevier Science B.V./ECNP

Serum nitric oxide metabolites in patients with multiple sclerosis

WOS: 000178933900007PubMed ID: 12383409Multiple sclerosis (MS) is an autoimmune disease of the central nervous system characterized by myelin breakdown. The free radical nitric oxide (NO), which is considered to be a major metabolite in immune function and in autoimmune disorders, is among the possible mediators causing the inflammatory reactions in MS. Consequently, NO has been implicated in the pathogenesis of MS and its animal model experimental allergic encephalomyelitis (EAE). In this study, stable metabolites of NO (NO2-+NO3-) levels were determined in sera of MS patients (n=23) and control subjects (n=16). NO2-+NO3- levels were higher in MS patients when compared to control subjects. However, there was not any correlation with serum NO2-+NO3- values and clinical features of the disease such as duration of sickness, the time elapsed from the last attack and EDSS values. Our results imply that nitric oxide may be involved in the pathogenesis of MS although further studies are required to elucidate underlying mechanisms. (C) 2002 Published by Elsevier Science Ltd

Involvement of nitric oxide in Parkinson's disease: Emphasis on sex difference in prevalence

WOS: 000182492100008Parkinson's disease (PD) is characterized by severe movement disorders. Excessive production of reactive oxygen species has been implicated as a possible mediator of neurodegenerative changes in nigrostriatal neurons in PD. Nitric oxide (NO) has received substantial attention among pathophysiological factors underlying glutamate neurotoxicity in neurodgenerative disorders including PD. PD is more prevalent in men than in women by an approximate 3:2 ratio; the nitrergic systems are also more active in males than females. In this study, NO2-+NO3- (stable metabolites of NO) levels were determined in sera of PD patients (n=20) and control subjects (n=16). NO2-+NO3- Levels were higher in PD patients compared to controls, and in males compared to females. Furthermore, there was a correlation between age and NO metabolites in females but not in males. These data support a role for NO in PD and provide further evidence for sex differences in NO activity that may underlie neurodegenerative disorders