Mammals, including humans, can synthesize the vitamin nicotinamide from tryptophan in the liver. The resultant nicotinamide is distributed to non-hepatic tissues. We have studied the effects of changes in tryptophan-nicotinamide metabolism on niacin nutritional status. The liver plays a critical role in nicotinamide supply. Animal studies showed that the tryptophan-nicotinamide pathway is affec...

The metabolism of nicotinic acid and nicotinamide has been examined in a number of mouse tissues following intraperitoneal injection of 0.9 pmole of W-labeled nicotinic acid and nicotinamide. In all the tissues except liver, and to some extent intestine, nicotinamide was clearly a better precursor of DPN than was nicotinic acid. In the case of liver and intestine [14C]nicotinic acid produced a ...

BACKGROUND Ventilator-induced lung injury is a form of acute lung injury that develops in critically ill patients on mechanical ventilation and has a high degree of mortality. Nicotinamide phosphoribosyltransferase is an enzyme that is highly upregulated in ventilator-induced lung injury and exacerbates the injury when given exogenously. Nicotinamide (vitamin B3) directly inhibits downstream pa...

Excess nicotinamide, a form of vitamin B3, is metabolized through two enzymatic systems and eventually excreted from the body. The first system starts with the methylation of nicotinamide by nicotinamide N-methyltransferase, which can subsequently be oxidized by aldehyde oxidase. The second enzymatic system oxidizes nicotinamide to nicotinamide N-oxide. It is located in the endoplasmic reticulu...

Excess nicotinamide, a form of vitamin B3, is metabolized through two enzymatic systems and eventually excreted from the body. The first system starts with the methylation of nicotinamide by nicotinamide N-methyltransferase, which can subsequently be oxidized by aldehyde oxidase. The second enzymatic system oxidizes nicotinamide to nicotinamide N-oxide. It is located in the endoplasmic reticulu...

Until recently it had been generally accepted that the formation of diphosphopyridine nucleotide in biological systems starts from nicotinamide, with nicotinamide riboside and nicotinamide mononucleotide as intermediates (Singer & Kearney, 1954). Much of the earlier work on whether nicotinic acid or nicotinamide is the more efficient precursor of diphosphopyridine nucleotide has been controvers...

Thirty-two cows, averaging 112 DIM, were assigned to four dietary treatments: 1) control, 2) Ca salts of fatty acids, 3) nicotinamide, and 4) Ca salts of fatty acids blended with nicotinamide during manufacture. Preliminary studies showed that nicotinamide survives blending with Ca salts of fatty acids during manufacture and that a blended mixture of nicotinamide and Ca salts of fatty acids gav...

Nicotinamide (vitamin B3) protects from ultraviolet (UV) radiation-induced carcinogenesis in mice and from UV-induced immunosuppression in mice and humans. Recent double-blinded randomized controlled Phase 2 studies in heavily sun-damaged individuals have shown that oral nicotinamide significantly reduces premalignant actinic keratoses, and may reduce new non-melanoma skin cancers. Nicotinamide...

BACKGROUND Both C-peptide and nicotinamide are known to reduce blood glucose in type 1 diabetes. In the present study, the effects of C-peptide alone or in combination with nicotinamide on glucose and insulin levels in streptozotocin-nicotinamide-induced type 2 diabetic mice. METHODS The study used 70 adult male NMARI mice, weighing 25-35 g, divided into seven groups: control; type 1 diabetic...

Although NAD(+) biosynthesis is required for Sir2 functions and replicative lifespan in yeast, alterations in NAD(+) precursors have been reported to accelerate aging but not to extend lifespan. In eukaryotes, nicotinamide riboside is a newly discovered NAD(+) precursor that is converted to nicotinamide mononucleotide by specific nicotinamide riboside kinases, Nrk1 and Nrk2. In this study, we d...