scholarly journals The activities of nicotinamide mononucleotide adenylyltransferase and of nicotinamide-adenine dinucleotide kinase in the livers of rats subjected to different hormonal treatments

1965 ◽  
Vol 96 (2) ◽  
pp. 507-516 ◽  
Author(s):  
AL Greenbaum ◽  
JB Clark ◽  
P McLean
2021 ◽  
Author(s):  
Masaki Igarashi ◽  
Masaomi Miura ◽  
Yoshiko Nakagawa-Nagahama ◽  
Keisuke Yaku ◽  
Kosuke Kashiwabara ◽  
...  

Abstract Preclinical studies have revealed that the elevation of nicotinamide adenine dinucleotide (NAD+) levels on administration of an NAD+ precursor, nicotinamide mononucleotide (NMN), can mitigate aging-related disorders; however, human data are sparse. Therefore, we aimed to investigate whether the chronic oral supplementation of NMN can elevate blood NAD+ levels and alter physiological dysfunctions, including muscle weakness, in healthy elderly participants. We administered 250 mg NMN per day to aged men for 6 or 12 weeks (n=21 for 6 weeks, n=10 for 12 weeks) in a placebo-controlled, randomized, double blind, parallel-group trial. Chronic supplementation with NMN was well tolerated and did not cause any significant deleterious effect. Metabolomic analysis of whole blood demonstrated that the oral supplementation of NMN significantly increased the concentrations of NAD+ and NAD+ metabolites. Moreover, NMN significantly improved muscle strength and performance, which were evaluated using the 30-second chair stand test, walking speed, and grip strength, and it showed no significant effect on body composition. Thus, our evidence indicates that chronic oral NMN supplementation can be an efficient NAD+ booster for preventing aging-related muscle dysfunctions in humans.


1970 ◽  
Vol 48 (12) ◽  
pp. 2267-2278 ◽  
Author(s):  
H. R. Godavari ◽  
E. R. Waygood

Leaves of wheat (Triticum aestivum L. var. Selkirk) were incubated with nicotinic acid-7-14C and nicotinamide-7-14C for varying time periods from 5 min to 12 h. Aliquots of alcoholic extracts of leaves were subjected to paper chromatography and radioautography to isolate the intermediates of the synthesis and breakdown of nicotinamide adenine dinucleotide. Nine compounds were isolated quantitatively and identified as intermediates in the pathway of NAD metabolism. All the intermediates were labeled rapidly and the rapidity of labeling became a problem in rigorously proving the sequential operation of the pathway. The results indicate that the Preiss-Handler pathway: nicotinic acid→nicotinic acid mononucleotide→nicotinic acid adenine dinucleotide→NAD operates in wheat leaves. The degradation of NAD proceeded from NAD→nicotinamide mononucleotide→nicotinamide riboside→nicotinamide. Deamidation of the nicotinamide to nicotinic acid initiated a fresh cycle of biosynthesis. The total radioactivity recovered in the intermediates indicates that no measurable amount was lost to other metabolic pathways. Nicotinamide is recovered without significant loss and recycled. The rapid appearance of labeled nicotinamide indicates a possible interconversion of nicotinic acid and nicotinamide. About 80% of the radioactivity accumulated was present in trigonelline which is considered, on the basis of other evidence, to be a non-toxic form of nicotinic acid. Benzimidazole treatment of the leaves increased the incorporation of 14C into NADP.


2020 ◽  
Vol 5 (3) ◽  
pp. 182-198
Author(s):  
Fatemeh Ghorbania ◽  
◽  
Masoomeh Ghorbani ◽  
Arezou Ghahghaee ◽  

Diabetes is a group of metabolic disorders characterized by a high blood sugar level over a prolonged period of time. Inhibition of carbohydrate hydrolyzing enzymes leads to decrease in the absorption of glucose which is considered as one of the effective managements of diabetes mellitus. Vegetable, fruit, milk and fish are good sources of nucleosides and inosine (INO), nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) with versatile health benefits. The well-adapted structural features of these compounds for the inhibition/activation of enzymes include several available hydrogen bond (H-bond) acceptors and donors, flexible backbone and hydrophobic nature. The substrates of α-amylase (α-Amy) and α-Glucosidase (α-Glu), known as key absorbing enzymes, have functional groups (OH groups) resembling nucleosides. Therefore, the present study was conducted to evaluate the inhibitory properties of nucleosides against αAmy and α-Glu. The median inhibition concentration (IC50) values for α-Glu in the presence of adenosine (ADN), adenosine triphosphate (AMP), NR, INO, adenosine triphosphate (ATP), nicotinamide adenine dinucleotide (NAD), Adenosine diphosphate (ADP)-ribose, ADP-glucose and NMN were determined 208.6±3.8, 254.1±5.2, 177.7±4.8, 192.1±5.2, 215.9±2.7, 65.4±1.3, 63.4±2.2, 75.6±4.2 and 196.1±2.6, respectively. The IC50 values α-Amy in the presence of ADN, AMP, NR, INO, ATP, NAD, ADP-ribose, ADP-glucose and NMN were determined 145.3±2.4, 202.3±3.9, 127.7±4.8, 163.5±3.6, 185.3±1.2, 80.4±2.8, 64.8±4.7, 51.1±1.6 and 166.5±1.4, respectively. Moreover, the Ki values of NAD were calculated as 13.8±0.8 and 18.6±2.4 µM for α-Glu and α-Amy in a competitive-mode and noncompetitive -mode inhibition. In addition, to communicate with the active site of α-Glu and α-Amy respectively, NR presented a binding energy of -7.8 and -6.8 kcal/mol, INO -7.3 and -6.9, ATP -8.3 and -7.3, NAD -10.0 and -8.5, ADP-ribose -8.7 and -7.4, ADP-glucose -8.9 and -7.6, cAMP -6.6 and -6.3 and NMN -6.8 and -7.0 kcal/mol. These antioxidant inhibitors may be potential anti-diabetic drugs, not only to reduce glycemic index, but also to limit the activity of the major reactive oxygen species (ROS) producing pathways. Key words: Nucleosides, NAD, hydrolyzing enzymes, enzyme inhibition, hyperglycemia


Author(s):  
Feng Pan ◽  
Shifei Kang ◽  
Yanfeng Zhao ◽  
Lei Dai ◽  
Qi Shao ◽  
...  

Nicotinamide mononucleotide (NMN) is an essential precursor of nicotinamide adenine dinucleotide (NAD+), which is an essential coenzyme for various physiological processes including energy metabolism, DNA repair, and cell growth.


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