Enhanced riboflavin incorporation into flavins in newborn riboflavin-deficient rats.

1977 ◽  
Vol 233 (5) ◽  
pp. E397
Author(s):  
C Muttart ◽  
R Chaudhuri ◽  
J Pinto ◽  
R S Rivlin
Keyword(s):  
Subcutaneous Injection ◽  
Flavin Adenine Dinucleotide ◽  
The Other ◽  
Flavin Mononucleotide ◽  
Newborn Rats ◽  
Riboflavin Deficiency ◽  
Riboflavin Deficient ◽  
Covalently Bound

The incorporation of a subcutaneous injection of [14C]riboflavin (2.5 muCi/100 g body wt) into flavin mononucleotide (FMN), flavin adenine dinucleotide (FAD), and flavins bound covalently to proteins was determined at 1, 6, and 18 h in liver, cerebrum, and cerebellum from progeny of normal and maternally riboflavin-deficient Holtzman rats. Radioactivity remaining as riboflavin was also determined under these circumstances. Experiments were initiated within 24 h of birth. In both groups of newborn rats, the incorporation of radioactive riboflavin into covalently bound flavins in liver and brain proceeded more slowly than into the other flavin fractions. In addition, radioactivity incorporated into covalently bound flavins comprised a relatively smaller proportion of the total amount incorporated in brain than in liver. In progeny of riboflavin-deficient dams, an increased rate of incorporation of riboflavin into all three flavin derivatives, particularly FAD, was observed in liver and brain, compared to results in normal progeny. These data provide evidence that maternal riboflavin deficiency enhances the incorporation of riboflavin into tissue flavins in liver, cerebrum, and cerebellum from newborn rats.

LIVER TRANSAMINASE ACTIVITY IN RIBOFLAVIN-DEFICIENT RATS

1962 ◽  
Vol 40 (8) ◽  
pp. 1065-1070 ◽  
Author(s):  
Sailen Mookerjea ◽  
S. C. Jamdar
Keyword(s):  
Protein Concentration ◽  
Flavin Adenine Dinucleotide ◽  
Alanine Transaminase ◽  
Transaminase Activity ◽  
Liver Transaminase ◽  
Liver Size ◽  
Riboflavin Deficient

Rats were deprived of riboflavin until there was established impairment of growth, hepatomegaly, and depletion of flavin–adenine dinucleotide and of catalase in the liver. Under these conditions there were increased concentrations of glutamic–aspartic and glutamic–alanine transaminases in the liver. With dietary depletion and repletion of protein the transaminase levels followed changes in liver size. Since the protein concentration in the liver was not affected, the level of transaminase was directly associated with the degree of anabolism. The changes in the glutamic–alanine transaminase were the more pronounced.

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.

scholarly journals Gamma Radiolysis of Flavin Mononucleotide and Flavin-Adenine Dinucleotide in Aqueous Solution

1991 ◽  
Vol 64 (8) ◽  
pp. 2532-2538 ◽  
Author(s):  
Abhijit Saha ◽  
Parikshit Chandra Mandal ◽  
Sudhindra Nath Bhattacharyya
Keyword(s):  
Aqueous Solution ◽  
Flavin Adenine Dinucleotide ◽  
Flavin Mononucleotide ◽  
Gamma Radiolysis

scholarly journals Glutathione peroxidase (EC 1.11.1.9) and superoxide dismutase (EC 1.15.1.1) activities in riboflavin-deficient rats infected with Plasmodium berghei malaria

1998 ◽  
Vol 79 (3) ◽  
pp. 305-309 ◽  
Author(s):  
D. A. Adelekan ◽  
D. I. Thurnham
Keyword(s):  
Superoxide Dismutase ◽  
Glutathione Peroxidase ◽  
Plasmodium Berghei ◽  
Control Group ◽  
Riboflavin Deficiency ◽  
Sod Activity ◽  
Parasite Protein ◽  
Riboflavin Deficient ◽  
Gpx Activity ◽  
Deficient Group

Riboflavin deficiency interferes with the growth and multiplication of malaria parasites as well as the host response to malaria. The objective of the present work was to determine the effects of riboflavin deficiency on erythrocyte glutathione peroxidase (EC1.11.1.9; GPx) and superoxide dismutase (EC1.15.1.1; SOD) in rats infected withPlasmodium bergheimalaria. Riboflavin in its co-enzyme form, FAD, is required by glutathione reductase (EC1.6.4.1) to regenerate GSH and GSH is an important cellular antioxidant both in its own right and also as a substrate for the enzyme GPx. Weanling rats were deprived of riboflavin for 8 weeks before intraperitoneal injection of 1 × 106P. bergheiparasites. Control animals were weight-matched to the respective riboflavin-deficient group. At 10d post-infection, parasite counts were higher in the weight-matched control group than the riboflavin-deficient group (P= 0.004). GPx activity was higher in erythrocytes of rats parasitized withP. bergheithan comparable non-infected rats regardless of riboflavin status (P< 0.05). As mature erythrocytes do not synthesize new protein, the higher GPx activities were probably due to the presence of the parasite protein. In erythrocytes from riboflavin-deficient rats, GPx activity tended to be lower than in those rats fed on diets adequate in riboflavin (weight-matched controls) whether parasitized or not, but the difference was not significant. Neither riboflavin deficiency nor malaria had any effect on erythrocyte SOD activity. It was concluded that riboflavin deficiency has no marked effect on erythrocyte GPx or SOD activity in the rat.

Covalently Bound Flavin in D-6-Hydroxynicotine Oxidase from Arthrobacter oxidans

1972 ◽  
Vol 27 (9) ◽  
pp. 1073-1074 ◽  
Author(s):  
M. Brühmüller ◽  
H. Möhler ◽  
K. Decker
Keyword(s):  
Amino Acid ◽  
Flavin Adenine Dinucleotide ◽  
Ph Dependence ◽  
Spectral Characteristics ◽  
Amino Acid Derivative ◽  
Aminopeptidase M ◽  
Arthrobacter Oxidans ◽  
Layer Chromatography ◽  
Hydrolysis Of ◽  
Covalently Bound

D-6-hydroxynicotine oxidase contains 1 mole of FAD covalently bound to one mole of enzyme. To identify the covalent linkage between FAD and protein, an amino acid derivative of riboflavin (HNO-flavin) was isolated and purified. It was obtained from flavin peptides by hydrolysis with 6 N HCl at 95°C or with aminopeptidase M. The riboflavin derivative had the spectral characteristics of 8α-substituted flavins. It showed a pH-dependence of fluorescence with a pK of 4.65 and 86% quenching at pH 7. In thin layer chromatography it was identical with 8α-(N-3-histidyl)-riboflavin. Hydrolysis of HNO-flavin in 6 N HCl at 125°C liberated 1 mole of histidine per mole of flavin as shown by amino acid analysis. Since FAD is the coenzyme of D-6-hydroxynicotine oxidase, these results are taken as evidence that this enzyme contains 8a- (N-3-histidyl) -flavin-adenine-dinucleotide in the active center.

The effect of pH and complexation on redox reactions between RS• radicals and flavins

1984 ◽  
Vol 62 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Rizwan Ahmad ◽  
David A. Armstrong
Keyword(s):  
Redox Potential ◽  
Linear Function ◽  
Redox Reactions ◽  
Flavin Adenine Dinucleotide ◽  
Protonated Form ◽  
Redox Properties ◽  
The Other ◽  
Effect Of Ph ◽  
Other Hand ◽  
High Redox Potential

Elementary considerations indicate that thiol radicals, RS•, should have a high redox potential [Formula: see text][Formula: see text]However, the equilibrium [4],[Formula: see text]which is established in the presence of excess RS−, would convert RS•to [Formula: see text] which is a reducing species. Experimentally it was demonstrated that thiol radicals made by γ radiolysis of β-mercaptoethanol solutions effected two-electron oxidation of dihydroflavin FlH2 at pH 6.3 and of FlH− at pH 8. On the other hand, [Formula: see text] readily reduced Fl to FlH2 or FlH− as expected. At pH 9, photostationary states were established after a few minutes radiolysis and the ratios [FlH−]ss/[Fl]ss were a function of [Formula: see text] The main reactions occurring were:[Formula: see text]The values of k19 and k22 were both large. The ratio k19/k22 was ∼0.8 for lumiflavin and ∼0.3 for flavin adenine dinucleotide. The cyclic disulphide anions of lipoamide and dithiothreitol [Formula: see text] also effected two-electron reductions of flavins. However, the protonated form of [Formula: see text] oxidized FlH2, and the photostationary ratio [FlH−]ss/[Fl]ss was an approximate linear function of [Formula: see text]. The implications of the observed changes in redox properties of sulphur radicals on complexation with RS− and protonation were briefly considered.Des considérations élémentaires indiquent que les radicaux thiyles, RS•, doivent avoir un potentiel rédox élevé [Formula: see text][Formula: see text]

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