scholarly journals Glutathione reductase deficiency in Saudi Arabia

1999 ◽  
Vol 5 (6) ◽  
pp. 1208-1212
Author(s):  
A. S. Warsy ◽  
M. A. El Hazmi
Keyword(s):  
Glutathione Reductase ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Normal Functioning ◽  
Riboflavin Deficiency ◽  
Males And Females ◽  
Presence And Absence ◽  
Glutathione Reductase Deficiency ◽  
The Stability ◽  
Riboflavin Deficient ◽  
Reduced Nicotinamide Adenine Dinucleotide

Glutathione reductase [GR]is a ubiquitous enzyme required for the conversion of oxidized glutathione [GSSG] to reduced glutathione [GSH] concomitantly oxidizing reduced nicotinamide adenine dinucleotide phosphate [NADPH]in a reaction essential for the stability and integrity of red cells. Mutations in the GR gene and nutritional deficiency of riboflavin, a co-factor required for the normal functioning of GR, can cause GR deficiency. We conducted a study on 1691 Saudi individuals to determine the overall frequency of GR deficiency and to identify whether the deficiency results from genetic or acquired causes or both. The activity of GR was measured in freshly prepared red cell haemolysate in the presence and absence of flavin adenine dinucleotide [FAD]and the activity coefficient [AC] was determined. Samples with low GR activity [>2.0 IU/g haemoglobin] both in the presence and absence of FAD and an AC between 0.9 and 1.2 were considered GR-deficient. Samples with AC >/= 1.3 were considered riboflavin-deficient. The overall frequency of partial GR deficiency was 24.5% and 20.3% in males and females respectively. In addition, 17.8% of males and 22.4% of females suffered from GR deficiency due to riboflavin deficiency. This could be easily corrected by dietary supplementation with riboflavin. No cases of severe GR deficiency were identified

scholarly journals DETERMINATION OF GLUTATHIONE REDUCTASE ACTIVITY IN MICROGRAM SAMPLES OF TISSUE, QUANTITATIVE HISTOLOGIC DISTRIBUTION OF THE ENZYME IN THE RAT ADRENAL AND EFFECT OF ADRENOCORTICOTROPIN

1968 ◽  
Vol 16 (3) ◽  
pp. 185-190 ◽  
Author(s):  
NORBERTO A. SCHOR ◽  
DAVID GLICK
Keyword(s):  
Glutathione Reductase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Reductase Activity ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Border Region ◽  
Nicotinamide Adenine ◽  
Subcutaneous Injections ◽  
Glutathione Reductase Activity ◽  
Reduced Nicotinamide Adenine Dinucleotide

A fluorometric method for determination of glutathione reductase activity in microgram samples of tissue, i.e., microtome sections, based on measurement of the decrease of reduced nicotinamide adenine dinucleotide phosphate due to its oxidation on reaction with oxidized glutathione, was developed and applied to the quantitative histologic distribution of the enzyme in the adrenal gland of the rat. Single subcutaneous injections of adrenocorticotropin in saline solution (25 mg/kg) produced little change of enzyme activity in any of the histologic zones, although there was some tendency for the peak activity to shift from fasciculata to the fascicular-reticular border region. The possible interrelationship of glutathione reductase with ascorbic acid and reduced nicotinamide adenine dinucleotide phosphate in adrenal function was considered.

scholarly journals Riboflavin deficiency in man: effects on haemoglobin and reduced glutathione in erythrocytes of different ages

1981 ◽  
Vol 46 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Hilary J. Powers ◽  
D. I. Thurnham
Keyword(s):  
Glutathione Reductase ◽  
Density Gradient ◽  
Aspartate Aminotransferase ◽  
Reduced Glutathione ◽  
Riboflavin Deficiency ◽  
Different Ages ◽  
Riboflavin Deficient

1. Erythrocytes (RBC) from control and marginally riboflavin-deficient subjects were fractionated into nine fractions using a discrete density gradient.2. Glutathione reductase (NAD(P)H: glutathione oxidoreductase;EC1.6.4.2) activity and aspartate aminotransferase (EC2.6.1.1) activity (with and without the appropriate co-enzymes) reduced glutathione, methaemoglobin, sulphaemoglobin and oxyhaemoglobin and susceptibility to peroxide were measured in RBC in the different fractions.3. Glutathione reductase and aspartate aminotransferase activities and concentrations of reduced glutathione and oxyhaemoglobin all declined with age, while melhaemoglobin, sulphaemoglobin and susceptibility to peroxide increased with age.4. The only significant differences noted in the RBC from marginally-riboflavin-deficient subjects by comparison with controls, were lower glutathione reductase activities and higher concentrations of methaemoglobin.5. The role of riboflavin in those sytems controlling RBC integrity is discussed.

scholarly journals THE EFFECT OF HEAT, INHIBITORS, AND RIBOFLAVIN DEFICIENCY ON MONOAMINE OXIDASE

1965 ◽  
Vol 43 (8) ◽  
pp. 1305-1318 ◽  
Author(s):  
Moussa B. H. Youdim ◽  
T. L. Sourkes
Keyword(s):  
Monoamine Oxidase ◽  
Chelating Agents ◽  
Liver Mitochondria ◽  
Borate Buffer ◽  
Rat Liver Mitochondria ◽  
Mitochondrial Enzyme ◽  
Riboflavin Deficiency ◽  
Different Types ◽  
The Stability ◽  
Riboflavin Deficient

The stability of monoamine oxidase of rat liver mitochondria to heating has been studied, using kynuramine as substrate in a spectrophotometric assay. After suspensions of mitochondria were heated for 50 minutes at 50°, about 30% of the enzymatic activity is lost; at 53° for the same time, 50% is lost. At 60° most of the activity is lost in the first 10 minutes. Activity as a function of pH was studied; resulting curves had a shoulder around pH 6.5 and a peak at pH 7.4 in phosphate buffer (or at 8.1 in borate buffer). The corresponding curves for heated suspensions of mitochondria (50°, 30 minutes) showed a relatively greater decrease in activity at pH 7.0 than at pH 6.5. This resulted in the disappearance of the shoulder and the appearance of a new peak at pH 6.5. Tranylcypromine and iproniazid inhibited the mitochondrial enzyme more strongly at pH 8.1 (borate buffer) than at the lower pH's, but pargyline inhibited more at pH 6.5. Chelating agents such as 8-hydroxyquinoline and thenoyltrifluoroacetone inhibited the enzyme more strongly at the lower pH's. Extracts of livers of riboflavin-deficient rats showed less activity than those from vitamin-supplemented animals. Substrates and certain inhibitors of monoamine oxidase protected the enzyme from inactivation during heating, but amines that are not substrates provided no such protection. Unsuccessful attempts were made to identify different types of monoamine oxidase activity in the mitochondria fractionated on sucrose density gradients.

Effect of Riboflavin Deficiency on the Metabolism of Oxypurines in Chicks

1971 ◽  
Vol 49 (12) ◽  
pp. 1059-1062 ◽  
Author(s):  
S. T. Chou
Keyword(s):  
Uric Acid ◽  
Acid Synthesis ◽  
Xanthine Dehydrogenase ◽  
Broiler Chicks ◽  
Uric Acid Concentration ◽  
Riboflavin Deficiency ◽  
Deficient Diet ◽  
High Incidence ◽  
Liver And Kidney ◽  
Riboflavin Deficient

Day-old broiler chicks of both sexes were used in three experiments to determine the effect of riboflavin deficiency on oxypurine metabolism catalyzed by xanthine dehydrogenase, a riboflavin-containing enzyme. Chicks fed a riboflavin-deficient diet (1.38 mg/kg) for 3 weeks exhibited depressed growth and a high incidence of curled-toe paralysis (higher than 80%) as compared to control chicks (15.1 mg riboflavin per kilogram diet; no incidence of curled-toe paralysis). In addition, the precursors of uric acid, hypoxanthine and/or xanthine, accumulated in the liver and kidney of deficient chicks showing curled-toe paralysis. These observations show that dietary riboflavin being incorporated into xanthine dehydrogenase is essential for oxypurine metabolism. Moreover in the chick, the liver and the kidney may be important sites of uric acid synthesis. The low uric acid concentration in the plasma of the deficient chicks appeared to be indicative of a disturbance in uric acid synthesis in the liver and kidney.

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