Role of glucose cycloacetoacetate hydrolysate on tyrosine oxidation

1970 ◽  
Vol 48 (10) ◽  
pp. 1178-1180
Author(s):  
M. C. Nath ◽  
Idrees Bhai
Keyword(s):  
Ascorbic Acid ◽  
Enzyme Activity ◽  
Guinea Pigs ◽  
Acid Oxidase ◽  
Tyrosine Oxidation

In the livers of the scorbutic guinea pigs the activity of p-hydroxyphenylpyruvic acid oxidase was found to remain unchanged but profoundly reduced after the feeding of extra tyrosine. Glucose cycloacetoacetate hydrolysate, a reducing compound, when ingested simultaneously with tyrosine was found to prevent the reduction in the enzyme activity. This effect was comparable to that of ascorbic acid.

D-Serine metabolism: new insights into the modulation of D-amino acid oxidase activity

2013 ◽  
Vol 41 (6) ◽  
pp. 1551-1556 ◽  
Author(s):  
Silvia Sacchi
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Oxidase Activity ◽  
Acid Oxidase ◽  
Endogenous Ligand ◽  
Amino Acid Oxidase ◽  
The Brain ◽  
Serine Metabolism ◽  
Synthesis And Degradation

Over the years, accumulating evidence has indicated that D-serine represents the main endogenous ligand of NMDA (N-methyl-D-aspartate) receptors. In the brain, the concentration of D-serine stored in cells is defined by the activity of two enzymes: serine racemase (responsible for both the synthesis and degradation) and D-amino acid oxidase (which catalyses D-serine degradation). The present review is focused on human D-amino acid oxidase, discussing the mechanisms involved in modulating enzyme activity and stability, with the aim to substantiate the pivotal role of D-amino acid oxidase in brain D-serine metabolism.

The formation of choleglobin and the role of catalase in the erythrocyte

1949 ◽  
Vol 136 (884) ◽  
pp. 435-448 ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Ascorbic Acid ◽  
Amino Acid ◽  
Catalase Activity ◽  
Acid Oxidase ◽  
Small Decrease ◽  
Amino Acid Oxidase ◽  
Oxidase System ◽  
Inverse Proportion

In haemolysates of non-nucleated erythrocytes there is an inverse proportion between catalase activity and rate of choleglobin formation on addition of ascorbic acid. In the intact erythrocytes catalase protects haemoglobin against oxidation and further destruction by the hydrogen peroxide generated by the D-amino-acid oxidase system or by physiological concentrations of ascorbic acid and glutathione. Acid destromatization of haemolyzed horse erythrocytes causes a small decrease in the catalase activity and an increased rate of inactivation of the remaining catalase by ascorbic acid. The liberation of copper from haemocuprein is quantitatively insufficient to explain the decreased stability of the catalase. Exposing duck oxyhaemoglobin, but not reduced haemoglobin, to a pH of 5⋅5 to 5⋅8, causes an alteration which is apparent from the increase of the rate of choleglobin formation. The mechanism of this alteration is discussed. It partly explains the 'stroma effect', at least in duck erythrocytes. In addition, in the latter, there is a true stroma effect. Choleglobin formation in the presence of ascorbic acid is accelerated by a variety of substances. Some of these perturb haemoglobin, while others increase the formation of hydrogen peroxide from ascorbic acid. The implications of our findings on the mechanism of choleglobin formation and on the role of catalase in the erythrocyte are discussed.

scholarly journals In Vivo Cultivation of Leukocytes in Diffusion Chambers: Requirement of Ascorbic Acid for Differentiation of Mononuclear Leukocytes to Fibroblasts

Blood ◽  
1961 ◽  
Vol 18 (3) ◽  
pp. 310-316 ◽  
Author(s):  
NICHOLAS L. PETRAKIS
Keyword(s):  
Ascorbic Acid ◽  
Guinea Pigs ◽  
Mononuclear Leukocytes ◽  
Diffusion Chambers ◽  
Nuclear Enlargement

Abstract Studies were made to evaluate the influence of ascorbic acid upon the differentiation of mononuclear leukocytes to fibroblasts when cultivated in diffusion chambers, in vivo. Ascorbic acid-depleted leukocytes grown in ascorbic acid-deficient host guinea pigs developed into abnormal cellular forms characterized by nuclear enlargement, multipolar mitoses, and giant forms These changes could be reversed by treatment of the host guinea pigs with ascorbic acid. The findings indicate a direct cellular role of ascorbic acid in the differentiation of mononuclear leukocytes to fibroblasts.

scholarly journals Experimental Megaloblastic Anemia in Young Guinea Pigs

Blood ◽  
1956 ◽  
Vol 11 (2) ◽  
pp. 123-142 ◽  
Author(s):  
ROLV K. SLUNGAARD ◽  
GEORGE M. HIGGINS
Keyword(s):  
Ascorbic Acid ◽  
Vitamin B12 ◽  
Peripheral Blood ◽  
Guinea Pigs ◽  
Megaloblastic Anemia ◽  
Bacterial Flora ◽  
Spontaneous Remission ◽  
Mild Degree ◽  
Pathologic State

Abstract Megaloblastosis has been produced in young guinea pigs by feeding them purified diets deficient its pteroylglutamic acid (PGA) or vitamin B12 or both. The withholding of ascorbic acid from the diet did not produce megaloblastosis but it greatly enhanced its development when PGA was also withheld. Spontaneous remission took place in several instances. The possible role of growth of the animal and changes in the bacterial flora of the gastrointestinal tract has been discussed. Bacteriologic studies appeared to indicate a possible interrelationship between the occurrence of Escherichia coli in the stools of guinea pigs consuming deficient diets and the development of megaloblastosis. Diarrhea and infections are considered important in the pathogenesis of megaloblastic anemia but infections were not observed in animals of the present study. However, diarrhea was a prominent feature and appeared to be a factor associated with megaloblastosis. Anemia was usually present in association with megaloblastosis; however, megaloblastosis of a mild degree appearing in some of the animals fed the diets deficient in PGA or vitamin B12 was not accompanied by anemia. When ascorbic acid was withheld in addition, then anemia always developed. A dimorphic picture of macrocytosis and microcytosis was found most commonly in the peripheral blood of animals with megaloblastosis. This has been explained on the basis of regenerative macrocytosis or as a disturbance of the maturation of erythrocytes in such deficiencies. Data obtained from peripheral blood are not a reliable indicator of megaloblastosis, nor is the clinical condition of the animal indicative of the pathologic state. One animal which had been fed a diet deficient in vitamin B12 and PGA and which showed megaloblasts in its bone marrow was given injections of vitamin B12. The megaloblastosis was corrected but the animal died on the sixteenth day of treatment. Two animals fed diets deficient in PGA and ascorbic acid were subsequently given injections of PGA and ascorbic acid. The results demonstrated that administration of ascorbic acid alone did not interrupt the development of severe megaloblastosis in the continuing absence of PGA. When PGA was given, reticuocytosis then ensued and there was a reversal of megaloblastic erythropoiesis.

Role of Castration and Androgens in D-Amino Acid Oxidase Activity of Tissues

1956 ◽  
Vol 185 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Barbara R. Endahl ◽  
Charles D. Kochakian
Keyword(s):  
Enzyme Activity ◽  
Amino Acid ◽  
Guinea Pig ◽  
Oxidase Activity ◽  
The Other ◽  
Maximum Effect ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Small Doses

A large number of C19 steroids were able to markedly increase the d-amino acid oxidase activity of the kidney of the castrated mouse. The maximum effect was attained within 21 days of treatment and with relatively small doses of the most potent androgens. On the other hand, neither castration nor various androgens were able to significantly alter the d-amino acid oxidase activity of either the kidney or liver of the castrated rat and guinea pig. Furthermore, age did not influence the enzyme activity of the tissues of the rat (2–8 months of age) or the guinea pig (4–8 months of age). Estradiol produced a small increase in the d-amino acid oxidase activity of the kidney of the mouse but estrone, methoxybisdehydrodiosynolic acid and several corticoids were ineffective.

scholarly journals Effects of Phosphorus Level on Quality Traits and Quality-Related Enzymatic Activity in Lettuce

2021 ◽  
Author(s):  
Guang-Shu Ma ◽  
Hua Lian
Keyword(s):  
Ascorbic Acid ◽  
Enzyme Activity ◽  
Nitrate Reductase ◽  
Plant Growth ◽  
Enzymatic Activity ◽  
Nitrate Content ◽  
Acid Oxidase ◽  
Quality Traits ◽  
Phosphorus Level ◽  
Related Enzyme

Abstract In this experiment, we studied the effects of the application of various amounts phosphorus on the quality traits and quality-related enzyme activity in lettuce. When we supplied lettuce with 0.3 mmol/L or 0.4 mmol/L phosphorus, the yield was higher than that of the control. In addition, the quality traits were better, the nitrate content was lower and the nitrate reductase, catalase and ascorbic acid oxidase activities were higher in these plants than in the control. In addition, the chlorophyll content was higher, and the root activity was stronger, in plants supplied with 0.3 or 0.4 mM/L phosphorus than in the control. These results suggest that the application of 0.3 or 0.4 mM/L phosphorus to lettuce is optimal for plant growth.

Wound Contraction in Relation to Collagen Formation in Scorbutic Guinea-pigs

Development ◽  
1956 ◽  
Vol 4 (2) ◽  
pp. 167-175
Author(s):  
M. Abercrombie ◽  
M. H. Flint ◽  
D. W. James
Keyword(s):  
Ascorbic Acid ◽  
Guinea Pigs ◽  
Wound Contraction ◽  
Skin Wounds ◽  
Collagen Fibres ◽  
Collagen Formation ◽  
Effective Force ◽  
Mobile Part ◽  
Centripetal Movement

A Wound in any mobile part of the skin of a mammal diminishes in area as it heals by a centripetal movement of the undamaged skin surrounding it. This movement, usually called wound contraction, depends on a pull exerted by the material within the wound (Lindquist, 1946; Abercrombie, Flint, & James, 1954; Billingham & Medawar, 1955). It is commonly believed that the effective force is developed by the newly formed collagen fibres. In a previous paper, however (Abercrombie, Flint, & James, 1954), we found that the course of the contraction of skin wounds in rats did not parallel the deposition of new collagen, chemically measured. This result, while certainly in no way conclusive by itself, suggested that the supposed role of collagen in contraction ought to be tested more stringently. This we have now done by measuring wounds made on guinea-pigs receiving a diet devoid of ascorbic acid.

Sign in / Sign up

Export Citation Format

Share Document