The apparent conversion of tryptophan to nicotinic acid has been observed for several animal species (cf. (1)). Other studies demonstrated that at least some of the nicotinic acid (or amide) was synthesized within the tissues of the animal (2, 3). It was of interest to extend these studies and the ability of liver slices to synthesize nicotinic acid from its biologically active intermediate, 3-...

Alcohol consumption causes nicotinic acid deficiency. The present study was undertaken to determine whether dietary nicotinic acid supplementation provides beneficial effects on alcohol-induced endotoxin signaling and the possible mechanisms at the gut-liver axis. Male Sprague-Dawley rats were pair-fed the Lieber-DeCarli liquid diets containing ethanol or isocaloric maltose dextrin for eight we...

In cereals, nicotinic acid occurs mainly in a bound form, niacytin, which is nutritionally unavailable to certain bacteria and mammals (Kodicek & Wilson, 1960). Most published findings relating to nutritional availability have been on rats and pigs, and the results have been in agreement with microbiological assays (Braude, Kon, Mitchell & Kodicek, 1955 ; Kodicek, Braude, Kon & Mitchell, 1956, ...

It has been reported that intravenous injection of nicotinic acid produces hypoglycemia in normal humans (l-4). A definite improvement in the carbohydrate tolerance of diabetic patients after administration of nicotinic acid has also been reported (4). It was therefore of interest to study the urinary excretion of nicotinic acid in diabetic patients. In the chemical estimation of nicotinic acid...

Krehl et al. (1, 2) have observed that the inclusion of large amounts of corn grits in a low protein diet produced a growth retardation in rats, which was corrected by the addition of either nicot,inic acid or L-tryptophan. The beneficial action of the amino acid is now attributed to its role as a biological precursor of nicotinic acid (3-5). It is not necessary to postulate the existence of a ...

Previous reports from this laboratory have described the isolation of 6-hydroxynicotinic acid and 6-0x0-1 ,4,5,6-tetrahydronicotinic acid from the reaction media of a clostridial species grown on nicotinic acid (1). Bn enzyme that catalyzes the reversible oxidation of nicotinic acid to HNA’ has been purified from extracts of this microorganism (2). Since fortified crude extract of this Clostrid...

Previous reports from this laboratory have described the isolation of 6-hydroxynicotinic acid and 6-0x0-1 ,4,5,6-tetrahydronicotinic acid from the reaction media of a clostridial species grown on nicotinic acid (1). Bn enzyme that catalyzes the reversible oxidation of nicotinic acid to HNA’ has been purified from extracts of this microorganism (2). Since fortified crude extract of this Clostrid...

Nicotinic acid is one of the most effective agents for both lowering triglycerides and raising HDL. However, the side effect of cutaneous flushing severely limits patient compliance. As nicotinic acid stimulates the GPCR GPR109A and Gi/Go proteins, here we dissected the roles of G proteins and the adaptor proteins, beta-arrestins, in nicotinic acid-induced signaling and physiological responses....

The time course of the nicotinic acid-induced changes in levels of plasma free fatty acids (FFA) was examined. The plasma FFA response of fasted dogs to graded doses of nicotinic acid was shown to be biphasic: an initial depression of the level of plasma FFA was followed by a rebound elevation to supernormal levels. FFA rebound was not seen after the administration of the nicotinic acid homolog...

Since the observation (1) that tryptophan and nicotinic acid are mutually interchangeable, within limits, in supporting the growth of rats, considerable evidence has accumulated which indicates that biosynthesis of nicotinic acid can proceed from tryptophan (2-5). Unequivocal evidence for this transformation was provided by the experiments of Heidelberger et al. (6) who fed labeled tryptophan @...