Effect of the component parts of nicotinamide adenine dinucleotide (NAD⊕) as inhibitors of lactic dehydrogenase

1967 ◽  
Vol 56 (6) ◽  
pp. 763-765 ◽  
Author(s):  
Albert J. Forlano
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Lactic Dehydrogenase ◽  
Nicotinamide Adenine

scholarly journals The ultrastructural cytochemistry of lactic dehydrogenase, succinic dehydrogenase, dihydro-nicotinamide adenine dinucleotide diaphorase and cytochrome oxidase activities in hair cell mitochondria of the guinea pig cochlea.

1975 ◽  
Vol 23 (3) ◽  
pp. 216-234 ◽  
Author(s):  
G J Spector
Keyword(s):  
Hair Cell ◽  
Cytochrome Oxidase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Succinic Dehydrogenase ◽  
Lactic Dehydrogenase ◽  
Nicotinamide Adenine ◽  
Fixation Method ◽  
Inner Mitochondrial Membrane ◽  
Tetrazolium Chloride ◽  
Outer Compartment

The use of cinnamyl nitroblue tetrazolium chloride (DS-NBT) in dehydrogenase experiments (lactic dehydrogenase, succinic dehydrogenase, nicotinamide adenine dinucleotide diaphorase) and 3,3'-diaminobenzidine tetrahydrochloride (DAB) in cytochrome oxidase experiments indicated that mitochondrial oxidoreduction reactions from nicotinamide adenine dinucleotide to cytochrome oxidase are located on the inner mitochondrial membrane in the outer compartment and the intracristate spaces. These reactions behave according to the chemiosmotic hypothesis. The cochlear hair cell mitochondria are cytochemically indistinguishable from free liver mitochondria. The heterogeneous mitochondrial staining pattern is related to the osmolarity of the incubation media, solubility of the enzymes and pH of the medium, but not to the fixation method.

A Continuous Spectrophotometric Method for the Determination of Leucine Aminopeptidase

1968 ◽  
Vol 14 (6) ◽  
pp. 555-564 ◽  
Author(s):  
J A Knight ◽  
D T Hunter
Keyword(s):  
Spectrophotometric Method ◽  
Nicotinamide Adenine Dinucleotide ◽  
Leucine Aminopeptidase ◽  
Lactic Dehydrogenase ◽  
New Method ◽  
Nicotinamide Adenine ◽  
Glutamic Pyruvic Transaminase ◽  
Peptide Hydrolase ◽  
Reduced Nicotinamide Adenine Dinucleotide

Abstract A new method to assay the enzyme, leucine aminopeptidase (LAP; L-leucyl-peptide hydrolase—3.4.1.1), is described. The technic is an extension of the conventional glutamic-pyruvic transaminase (GPT) reaction. Serum LAP is allowed to react with the substrate L-leucyl-L-alanine to quantitatively generate alanine. This alanine, in the presence of excess α-ketoglutaric acid and GPT, rapidly forms pyruvate, which is converted to lactate by excess lactic dehydrogenase (LDH). Reduced nicotinamide adenine dinucleotide (NAD) is quantitatively oxidized in this reaction. The change in reduced NAD concentration is followed by continuous spectrophotometry at 340 mµ.

Lactic Dehydrogenase Inhibitors in NAD

1970 ◽  
Vol 16 (3) ◽  
pp. 254-255 ◽  
Author(s):  
Arthur L Babson ◽  
Elsa G Arndt
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Lactic Dehydrogenase ◽  
Nicotinamide Adenine ◽  
High Concentration ◽  
Kinetic Assay ◽  
Colorimetric Procedure

Abstract Commercial samples of nicotinamide adenine dinucleotide (NAD) contain various amounts of one or more lactic dehydrogenase (LDH) inhibitors but not the inhibitor described in the reduced coenzyme, NADH. The kinetic assay for LDH, in which a high concentration of NAD is used, was more seriously influenced by the source of NAD than a tetrazolium-coupled colorimetric procedure that requires much less coenzyme.

scholarly journals The Role of Oxidized Nicotinamide Adenine Dinucleotide in Fluoride Inhibition of Active Sodium Transport in Human Erythrocytes

1972 ◽  
Vol 60 (3) ◽  
pp. 337-350 ◽  
Author(s):  
Marshall S. Millman ◽  
Akira Omachi
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Rate Coefficient ◽  
Phosphoglycerate Kinase ◽  
Lactic Dehydrogenase ◽  
Human Erythrocytes ◽  
Nicotinamide Adenine ◽  
Direct Inhibition ◽  
Reaction Sequence ◽  
Induced Changes

The rate coefficient for 22Na release from previously labeled human erythrocytes was determined in the presence of 0.1–10 mM sodium fluoride (F). The oxidized nicotinamide adenine dinucleotide (NAD+) level at the end of 2 hr of incubation in tris(hydroxymethyl)aminomethane (Tris)-Ringer medium was also measured. Both parameters decreased proportionately as F concentration was raised. Both F-induced changes were immediate and were reversed by 10 mM pyruvate. The decrease in NAD+ concentration following enolase inhibition by F is attributed to a diminished rate of formation in the reaction catalyzed by lactic dehydrogenase (LDH) with undiminished continued utilization in the reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase (GAPDH). It is postulated that the NAD+ lowering limited the GAPDH step, resulting in proportionate decreases in the rates of phosphoglycerate kinase (PGK) and Na,K-dependent adenosine triphosphatase (Na,K-ATPase), a reaction sequence thought to link glycolysis with active Na extrusion. Adding pyruvate with F increased NAD+ production at the LDH step, thus reactivating GAPDH, PGK, and Na,K-ATPase and leading to the observed restoration of 22Na release. The results suggest, therefore, that F inhibits active Na transport in intact human erythrocytes indirectly through a lowering of NAD+, although, direct inhibition of the Na,K-ATPase by F may possibly occur simultaneously.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

Nicotinamide Adenine Dinucleotide and the Metabolism of Ethanol and Acetaldehyde

1967 ◽  
Vol 28 (2) ◽  
pp. 213-224 ◽  
Author(s):  
E. Majchrowicz ◽  
B. L. Bercaw ◽  
W. M. Cole ◽  
D. H. Gregory
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine
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