Human kidney proximal tubules are the main source of plasma glutathione peroxidase

Avissar, Nelly E.; Ornt, Daniel B.; Yagil, Yoram; Horowitz, Stuart; Watkins, Richard H.; Kerl, E. A.; Takahashi, Kazuhiko; Palmer, I. S.; Cohen, Harvey J.

doi:10.1152/ajpcell.1994.266.2.c367

Cited by 302 publications

(221 citation statements)

References 25 publications

Supporting

Mentioning

201

Contrasting

Unclassified

Order By: Relevance

“…The glutathione peroxidase family has at least four member enzymes, but little is known about their physiological function. Extracellular glutathione peroxidase is the predominant form in plasma and is mainly produced in the kidney (Avissar et al, 1989;Huang & A Ê kesson, 1993;Avissar et al, 1994;Huang, 1996), and it is also found in milk (Avissar et al, 1991) and aqueous humor (Huang et al, 1997). It is also the major 75 Se-substituted protein secreted by human thyrocytes incubated with ( 75 Se)selenite, and it was hypothesized that it may be a regulator of thyroid hormone synthesis (Howie et al, 1995).…”

Section: Discussionmentioning

confidence: 99%

Plasma levels of selenium, selenoprotein P and glutathione peroxidase and their correlations to fish intake and serum levels of thyrotropin and thyroid hormones: A study on Latvian fish consumers

et al. 1998

View full text Add to dashboard Cite

Objective: To study the relationships between ®sh intake and different markers of selenium status and thyroid hormone function. Design: Cross-sectional study. Setting and subjects: Sixty-eight men (age 24±79 years) were recruited among coastal ®shermen and inland subjects from Latvia. None of the subjects was on selenium medication or had any known endocrine disease. Main outcome measures: Correlations between ®sh intake, plasma levels of selenium, selenoprotein P, glutathione peroxidase, organic mercury in erythrocytes and TSH in serum. Results: Selenium in plasma ranged from 0.30 to 1.56 mmola1, selenoprotein P from 0.54 to 2.21 arbitrary units relative to pooled plasma, and glutathione peroxidase from 1.20 to 5.73 mga1. The number of ®sh meals per month was correlated with plasma selenium, selenoprotein P and glutathione peroxidase (r 0.63, r 0.62 and r 0.50, respectively; P`0.001). Plasma selenium was correlated with selenoprotein P and glutathione peroxidase (r 0.88 and r 0.67, respectively; P`0.001), and also selenoprotein P and glutathione peroxidase were correlated (r 0.63, P`0.001). The mean plasma selenium level in those with a high ®sh intake (21±50 ®sh mealsamonth), was 81% higher than in those with lowest ®sh intake. TSH in serum was inversely correlated with plasma selenium and selenoprotein P. Thyroid hormone levels were not correlated with plasma selenium, selenoproteins or ®sh intake. Conclusions: In this study group, selenium from ®sh intake had a marked impact on all variables studied on selenium status. No impact of selenium status on T3 and T4 levels was observed. The slightly negative correlation of selenium status with TSH levels might indicate a higher TSH secretion at low selenium status.

show abstract

Section: Discussionmentioning

confidence: 99%

Plasma levels of selenium, selenoprotein P and glutathione peroxidase and their correlations to fish intake and serum levels of thyrotropin and thyroid hormones: A study on Latvian fish consumers

et al. 1998

View full text Add to dashboard Cite

show abstract

“…Plasma GPx activity is largely derived from the renal tubular epithelium (19). Both plasma and erythrocyte GPx activity change in relation to the evolution of renal disease (20 -22).…”

Section: Statisticsmentioning

confidence: 99%

Race-Specific Differences in Antioxidant Enzyme Activity in Patients With Type 2 Diabetes

et al. 2005

View full text Add to dashboard Cite

OBJECTIVE -Lipid hydroperoxide, a marker of oxidative stress, is linked to the development of nephropathy and is reportedly higher in patients of African origin compared with Caucasians. This may be relevant to race-specific differences in susceptibility to nephropathy. We investigated whether alterations in antioxidant enzyme activity could account for this biochemical phenotype and examined the relationship with conventional markers of renal disease.RESEARCH DESIGN AND METHODS -Two hundred seventeen individuals were studied. Patients with type 2 diabetes (n ϭ 75) of African and Caucasian origin were matched by sex and racial origin with healthy control subjects (n ϭ 142). Plasma total superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity were spectrophotometrically measured, and total cholesterol and triglycerides were measured by enzymatic methods.RESULTS -SOD activity was higher and GPx activity lower in patients with diabetes than in healthy control subjects (573 Ϯ 515 vs. 267 Ϯ 70 units/l, P Ͻ 0.001 and 150 Ϯ 93 vs. 178 Ϯ 90 units/l, P ϭ 0.019, respectively). Patients of African origin with diabetes had lower GPx and higher SOD activity compared with Caucasian patients (126 Ϯ 82 vs. 172 Ϯ 97 units/l, P ϭ 0.03 and 722 Ϯ 590 vs. 445 Ϯ 408 units/l, P ϭ 0.002, respectively). Patients of African origin with normal urinary albumin excretion had significantly higher plasma creatinine concentrations (100.7 Ϯ 14.2 vs. 88.1 Ϯ 14.9 mol/l, P ϭ 0.007) and lower GPx activity (99.0 Ϯ 72.4 vs. 173.7 Ϯ 107.4 units/l, P ϭ 0.02) compared with those of Caucasian origin. African origin was an independent predictor of elevated SOD (P ϭ 0.007) and reduced GPx activity (P ϭ 0.02) in regression analysis.CONCLUSIONS -SOD and GPx enzyme activities vary according to race and could account for differences in lipid hydroperoxide. In patients of African origin, susceptibility to renal disease may be associated with lowered GPx activity. Diabetes Care 28:1698 -1703, 2005P eople of African origin have an increased susceptibility to renal disease compared with Caucasians. In the U.K. and U.S., there is a four-to sixfold difference in the incidence of endstage renal disease due to diabetic nephropathy (1-3). The higher prevalence of end-stage renal disease in patients of African origin exceeds that which is explained by the prevalences of hypertension and diabetes.Plasma measures of oxidative stress are increased in patients with diabetes compared with control subjects (4). A nonspecific lipid peroxidation product, malonyldialdehyde, which is indicative of oxidant stress and advanced glycation end products, localizes in the nodular glomerular lesions characteristic of diabetic nephropathy (5-7). Free radicals are also implicated in endothelial and basement membrane damage and, as such, are pathophysiologically related to increased urinary albumin excretion, the most powerful marker of the onset and progression of diabetic nephropathy (8 -10).The major reactive oxygen species produced in the course of oxidative metabolism is s...

show abstract

“…16 Insignificant reduction levels of GSH-px were determined in patients on HD when compared with control group (p = 0.456) and in patients on CAPD when compared with HD (p = 0.425). Although contradictious results are present, most of other studies support our data.…”

Section: Discussionmentioning

confidence: 93%

“…[22][23][24][25][26] Antioxidant defense systems are less affected in patients on peritoneal dialysis than HD. [15][16][17] This is related to less frequent presence of anemia and moderate amount of lipid peroxidation. 23 Similarly, levels of SOD enzyme were significantly lower in patients on CAPD than HD.…”

Section: Discussionmentioning

confidence: 99%

Parameters of oxidative stress and echocardiographic indexes in patients on dialysis therapy

Kayabaşı

Şit²,

Atay

et al. 2010

Renal Failure

View full text Add to dashboard Cite

Aim: Quantity of oxidative stress (OS) is enhanced in every stage of chronic renal failure (CRF). OS and its effects on echocardiographic indexes in patients on hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) were evaluated. Materials and methods: Thirty-nine patients on CAPD, 32 patients on HD, and 30 healthy individuals with similar demographic features were included. Patients with diabetes mellitus and chronic inflammatory diseases were excluded. Blood samples were collected to examine hematological and biochemical parameters and levels of malonyldialdehyde (MDA), glutathione peroxidase (GSH-px), and superoxide dismutase (SOD) after a 12-hour fasting period in the middle of dialysis week. OS parameters were compared with ejection fraction (EF), interventricular septum diameter (IVSd), left ventricular posterior wall diameter (LVPWd), and left atrium diameter (LAd) determined in M-mod echocardiographic examination. Results: No significant difference was observed between MDA and GSH-px levels of patients and control group; however, SOD levels of patients group were significantly lower (p < 0.0001). SOD levels of patients on HD were lower than that of patients on CAPD (p = 0.039). No correlation was determined between antioxidants and cardiac indexes. Conclusion: SOD levels decreased significantly especially in patients on HD, and it was observed that lower levels of SOD would lead to OS in patients on HD and CAPD when compared to healthy individuals; MDA levels were independently influenced from EF.

show abstract

Human kidney proximal tubules are the main source of plasma glutathione peroxidase

Cited by 302 publications

References 25 publications

Plasma levels of selenium, selenoprotein P and glutathione peroxidase and their correlations to fish intake and serum levels of thyrotropin and thyroid hormones: A study on Latvian fish consumers

Plasma levels of selenium, selenoprotein P and glutathione peroxidase and their correlations to fish intake and serum levels of thyrotropin and thyroid hormones: A study on Latvian fish consumers

Race-Specific Differences in Antioxidant Enzyme Activity in Patients With Type 2 Diabetes

Parameters of oxidative stress and echocardiographic indexes in patients on dialysis therapy

Contact Info

Product

Resources

About