Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The calcium-dependent enzyme activity which hydrolyzes the p-nitrophenyl-O-P bond of paraoxon (paraoxonase) has been studied in several rat and human tissues. Rat plasma and liver showed the highest activities (1.31 +/- 0.19, 0.82 +/- 0.09 nmol/min mg protein +/- SEM, respectively), while other tissues showed less than 2% plasma activity. The Arrhenius plot showed monophasic patterns in both tissues with activation energy values of Ea = 57 +/- 3 and 69 +/- 4 kcal/mol degree K for rat liver and plasma, respectively. Rat plasma and liver paraoxonase lost about 80% activity after 24-hr storage at 27-30 degrees C and was not restored by calcium addition. There was no loss of activity in human serum after 3 days and only 33% after 5 days. The pH optimum for paraoxonase activities was about 7.4 for both rat tissues. It is concluded that plasma paraoxonase is similar to the liver enzyme and is a good mirror for total body detoxifying activity.
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PMID:Distribution and some biochemical properties of rat paraoxonase activity. 217 12

Serum paraoxonase (PON) is associated with plasma high density lipoproteins, and prevents the oxidative modification of low density lipoproteins. We have developed a sensitive sandwich enzyme-linked immunosorbent assay (ELISA), using two monoclonal antibodies against PON, to measure serum PON concentration. The concentration of PON in healthy Japanese subjects was 59.3 +/- 1.3 microgram/mL (mean +/- SEM; n = 87). Serum PON concentrations in relation to the PON 192 genetic polymorphism were: 69.5 +/- 2.9 microgram/mL in the QQ genotype; 63.0 +/- 1.9 microgram/mL in the QR genotype; and 52.8 +/- 1.7 microgram/mL in the RR genotype. Concentrations were significantly lower in the RR than in the QQ genotype (P < 0.01). Serum paraoxonase specific activity was higher in RR than in QQ subjects (18.6 +/- 0.40 vs. 2. 56 +/- 0.05 nmol/min/microgram, P < 0.01), but arylesterase specific activity was unrelated to genotype. PON concentration was positively associated (P < 0.001) with both serum arylesterase activity and, after adjusting for the effect of the position 192 polymorphism, with serum paraoxonase activity. Subjects with angiographically verified coronary heart disease had significantly lower PON concentrations than the healthy controls (52.0 +/- 2.3 microgram/mL; n = 35, P < 0.01). This association was independent of the position 192 genotype. Our new ELISA should be of value for epidemiologic and clinical studies of serum PON concentration. immunosorbent assay for human serum paraoxonase concentration.
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PMID:A sandwich enzyme-linked immunosorbent assay for human serum paraoxonase concentration. 1094 25

Apolipoprotein (apo) J, clusterin, is ubiquitously expressed in many tissues, and is a component of high-density lipoproteins (HDLs). There is experimental evidence that it may be anti-atherogenic through its effects on cholesterol transport, smooth muscle cell proliferation and lipid peroxidation. HDLs containing apo J and apo A-I carry paraoxonase (PON1), which protects low-density lipoproteins from oxidative modification; however, the extent to which apo J affects coronary heart disease (CHD) is not known. We have developed a sandwich ELISA that enables apo J to be assayed in the range of 13-200 microg/mL. Serum apo J was 52.8+/-0.8 microg/mL (mean+/-SEM; range, 36.0-84.3 microg/mL; n=92) in healthy Japanese men, and 49.3+/-0.5 microg/mL (34.5-72.8; n=241) in healthy Japanese women. Multiple regression of these data and results from 67 men with CHD showed that apo J concentration was unrelated to age, sex or body mass index, but was positively related to serum PON1 (p<0.001) and apo B (p<0.02) concentrations. In women, it was also positively related to blood glucose (p<0.02). After adjusting for its associations with covariates, serum apo J averaged 5.4 microg/mL, lower in CHD men than in controls (p<0.003). Type 2 diabetics had higher apo J concentrations (men, 83.1+/-3.4 microg/mL, n=64; women, 64.0+/-2.3 microg/mL, n=46) than healthy men and women (p<0.001). In these Type 2 diabetics, apo J concentration was unrelated to PON1 concentration, but was positively related to blood glucose (p<0.01). After adjustment for its relation to blood glucose, the mean apo J concentration was similar in diabetics and healthy subjects. These findings suggest that apo J may be anti-atherogenic in humans, and that its concentration is raised by Type 2 diabetes.
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PMID:Serum apolipoprotein j in health, coronary heart disease and type 2 diabetes mellitus. 1719 96

The amount of oxidative stress in severely traumatized patients is usually based on various individual parameters such as total antioxidants and lipid peroxidation. Serial measurements of plasma oxidation-reduction potential (ORP) in severely traumatized patients as a simple mean of assessing overall oxidative stress is described. Serial whole blood samples were obtained from multi-trauma patients (N=39) and healthy individuals (N=10). Plasma ORP in multi-trauma patients increased during the first few days of hospitalization and approached normal ORP levels upon discharge. On the ORP maxima day (5.8 days+/-0.5 SEM), a statistically significant decrease (p<0.05) was observed for negative acute phase reactants such as plasma paraoxonase-arylesterase (PON-AE) activity and total plasma protein in comparison with admission plasma levels. Monitoring ORP could be a useful tool for assessing the degree of oxidative stress, inflammation, severity of injury, and potential efficacy of treatment.
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PMID:Oxidation-reduction potential and paraoxonase-arylesterase activity in trauma patients. 1766 90