The effect of dietary protein and sulfur amino acids on hepatic glutathione concentration and glutathione-dependent enzyme activities in the rat

1988 ◽  
Vol 66 (8) ◽  
pp. 1048-1052 ◽  
Author(s):  
P. F. Bauman ◽  
T. K. Smith ◽  
T. M. Bray

Hepatic glutathione concentration and glutathione-dependent enzymes, glutathione S-transferase, glutathione peroxidase, and glutathione reductase, are important for protection against toxic compounds. Rats were fed diets containing 4, 7.5, 15, or 45% protein for 2 weeks. Glutathione and cysteine concentrations in rats fed the 4 and 7.5% protein diets were significantly lower (p < 0.05) than in rats fed the 15 and 45% protein diets. Glutathione S-transferase activity increased with increasing dietary protein. Glutathione peroxidase activity was significantly lower (p < 0.05) in rats fed 4 and 7.5% protein compared with rats fed 15 and 45% protein, whereas the activity of glutathione reductase was higher in rats fed 4 and 7.5% protein then in rats fed 15 or 45% protein. Dietary sulfur amino acids alone could account for the increase in glutathione concentration resulting from the increase in dietary protein from 7.5 to 15%. The limited availability of glutathione in animals fed the low protein diets could reduce the potential for detoxification of xenobiotics.

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2609
Author(s):  
Han Fang ◽  
Kirsten P. Stone ◽  
Sujoy Ghosh ◽  
Laura A. Forney ◽  
Thomas W. Gettys

Dietary protein restriction and dietary methionine restriction (MR) produce a comparable series of behavioral, physiological, biochemical, and transcriptional responses. Both dietary regimens produce a similar reduction in intake of sulfur amino acids (e.g., methionine and cystine), and both diets increase expression and release of hepatic FGF21. Given that FGF21 is an essential mediator of the metabolic phenotype produced by both diets, an important unresolved question is whether dietary protein restriction represents de facto methionine restriction. Using diets formulated from either casein or soy protein with matched reductions in sulfur amino acids, we compared the ability of the respective diets to recapitulate the metabolic phenotype produced by methionine restriction using elemental diets. Although the soy-based control diets supported faster growth compared to casein-based control diets, casein-based protein restriction and soy-based protein restriction produced comparable reductions in body weight and fat deposition, and similar increases in energy intake, energy expenditure, and water intake. In addition, the prototypical effects of dietary MR on hepatic and adipose tissue target genes were similarly regulated by casein- and soy-based protein restriction. The present findings support the feasibility of using restricted intake of diets from various protein sources to produce therapeutically effective implementation of dietary methionine restriction.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Israel Pérez-Torres ◽  
Verónica Guarner-Lans ◽  
Alejandra Zúñiga-Muñoz ◽  
Rodrigo Velázquez Espejel ◽  
Alfredo Cabrera-Orefice ◽  
...  

We report the effect of cross-sex hormonal replacement on antioxidant enzymes from rat retroperitoneal fat adipocytes. Eight rats of each gender were assigned to each of the following groups: control groups were intact female or male (F and M, resp.). Experimental groups were ovariectomized F (OvxF), castrated M (CasM), OvxF plus testosterone (OvxF + T), and CasM plus estradiol (CasM + E2) groups. After sacrifice, retroperitoneal fat was dissected and processed for histology. Adipocytes were isolated and the following enzymatic activities were determined: Cu-Zn superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GR). Also, glutathione (GSH) and lipid peroxidation (LPO) were measured. In OvxF, retroperitoneal fat increased and adipocytes were enlarged, while in CasM rats a decrease in retroperitoneal fat and small adipocytes are observed. The cross-sex hormonal replacement in F rats was associated with larger adipocytes and a further decreased activity of Cu-Zn SOD, CAT, GPx, GST, GR, and GSH, in addition to an increase in LPO. CasM + E2exhibited the opposite effects showing further activation antioxidant enzymes and decreases in LPO. In conclusion, E2deficiency favors an increase in retroperitoneal fat and large adipocytes. Cross-sex hormonal replacement in F rats aggravates the condition by inhibiting antioxidant enzymes.


1989 ◽  
Vol 264 (3) ◽  
pp. 737-744 ◽  
Author(s):  
P Steinberg ◽  
H Schramm ◽  
L Schladt ◽  
L W Robertson ◽  
H Thomas ◽  
...  

The distribution and inducibility of cytosolic glutathione S-transferase (EC 2.5.1.18) and glutathione peroxidase (EC 1.11.1.19) activities in rat liver parenchymal, Kupffer and endothelial cells were studied. In untreated rats glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene and 4-hydroxynon-2-trans-enal as substrates was 1.7-2.2-fold higher in parenchymal cells than in Kupffer and endothelial cells, whereas total, selenium-dependent and non-selenium-dependent glutathione peroxidase activities were similar in all three cell types. Glutathione S-transferase isoenzymes in parenchymal and non-parenchymal cells isolated from untreated rats were separated by chromatofocusing in an f.p.l.c. system: all glutathione S-transferase isoenzymes observed in the sinusoidal lining cells were also detected in the parenchymal cells, whereas Kupffer and endothelial cells lacked several glutathione S-transferase isoenzymes present in parenchymal cells. At 5 days after administration of Arocolor 1254 glutathione S-transferase activity was only enhanced in parenchymal cells; furthermore, selenium-dependent glutathione peroxidase activity decreased in parenchymal and non-parenchymal cells. At 13 days after a single injection of Aroclor 1254 a strong induction of glutathione S-transferase had taken place in all three cell types, whereas selenium-dependent glutathione peroxidase activity remained unchanged (endothelial cells) or was depressed (parenchymal and Kupffer cells). Hence these results clearly establish that glutathione S-transferase and glutathione peroxidase are differentially regulated in rat liver parenchymal as well as non-parenchymal cells. The presence of glutathione peroxidase and several glutathione S-transferase isoenzymes capable of detoxifying a variety of compounds in Kupffer and endothelial cells might be crucial to protect the liver from damage by potentially hepatotoxic substances.


1993 ◽  
Vol 264 (6) ◽  
pp. G1057-G1065 ◽  
Author(s):  
C. Moundras ◽  
C. Remesy ◽  
C. Demigne

The aim of the present study was to evaluate the effect of changes in dietary protein level on overall availability of amino acids for tissues. For this purpose, rats were adapted to diets containing various concentrations of casein (7.5, 15, 30, and 60%) and were sampled either during the postprandial or postabsorptive period. In rats fed the protein-deficient diet, glucogenic amino acids (except threonine) tended to accumulate in plasma, liver, and muscles. In rats fed high-protein diets, the hepatic balance of glucogenic amino acids was markedly enhanced and their liver concentrations were consistently depressed. This response was the result of a marked induction of amino acid catabolism (a 45-fold increase of liver threonine-serine dehydratase activity was observed with the 60% casein diet). The muscle concentrations of threonine, serine, and glycine underwent changes parallel to plasma and liver concentrations, and a significant reduction of glutamine was observed. During the postabsorptive period, adaptation to high-protein diets resulted in a sustained catabolism of most glucogenic amino acids, which accentuated the drop in their concentrations (especially threonine) in all the compartments studied. The time course of metabolic adaptation from a 60 to a 15% casein diet has also been investigated. Adaptation of alanine and glutamine metabolism was rapid, whereas that of threonine, serine, and glycine was delayed and required 7-11 days. This was paralleled by a relatively slow decay of liver threonine-serine dehydratase (T-SDH) activity in contrast to the rapid adaptation of pyruvate kinase activity after refeeding a high-carbohydrate diet.(ABSTRACT TRUNCATED AT 250 WORDS)


1983 ◽  
Vol 29 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Carmine Di Ilio ◽  
Giovanni Polidoro ◽  
Arduino Arduini ◽  
Antonio Muccini ◽  
Giorgio Federici

2013 ◽  
Vol 59 (4) ◽  
pp. 443-451 ◽  
Author(s):  
E.A. Kosenko ◽  
L.A. Tikhonova ◽  
A.C. Poghosyan ◽  
Y.G. Kaminsky

Age of patients and brain oxidative stress may contribute to pathogenesis of Alzheimer's disease (AD). Erythrocytes (red blood cells, RBC) are considered as passive “reporter cells” for the oxidative status of the whole organism and are not well studied in AD. The aim of this work was to assess whether the antioxidant status of RBC changes in aging and AD. Blood was taken from AD and non-Alzheimer's dementia patients, aged-matched and younger controls. In vivo antioxidant status was assessed in each of the study subjects by measuring RBC levels of Н О , organic hydroperoxides, glutathione (GSH) and glutathione disulfide (GSSG), activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, and glucose-6-phosphate dehydrogenase. In both aging and dementia, oxidative stress in RBC was shown to increase and to be expressed in elevated concentrations of H O and organic hydroperoxides, decreased the GSH/GSSG ratio and glutathione S-transferase activity. Decreased glutathione peroxidase activity in RBC may be considered as a new peripheral marker for Alzheimer’s disease while alterations of other parameters of oxidative stress reflect age-related events.


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