OBJECTIVE Nicotinic acid (also known as niacin or vitamin B3), widely used to treat dyslipidemias, represents an effective and safe means to reduce the risk of mortality from cardiovascular disease. Nonetheless, a substantial fraction of patients discontinue treatment because of a strong side effect of cutaneous vasodilation, commonly termed flushing. In the present study, we tested the hypothe...

Nicotinic acid is a lipid-lowering agent widely used to treat hypertriglyceridemia and to elevate low high density lipoprotein levels. However, the underlying mechanisms are poorly understood. In this study, G protein activation by nicotinic acid and derivatives was assessed as stimulation of guanosine 5'-(gamma-[(35)S]-thio)triphosphate ([(35)S]GTPgammaS) binding, and [(3)H]nicotinic acid was ...

Nicotine and other nicotinic agonists have been found to improve performance on attention and memory tasks. Clinical studies using nicotine skin patches have demonstrated the efficacy of nicotine in treating cognitive impairments associated with Alzheimer's disease, schizophrenia, and attention-deficit/hyperactivity disorder. Experimental animal studies have demonstrated the persistence of nico...

ICOTINIC ACID and its derivatives occur in biologic materials as nicotinic acid, as nicotinamide, and in two co-enzymatic forms: diphosphopyridine nucleotide (DPN), and triphosphopyridine nucleotide (TPN). Among mammals, only man and dog are known to develop syrnptoms of nicotinic acid deficiency. In man, deficiency results in dermatitis, diarrhea, delirium, and death. Recently, nicotinic acid ...

Although the bacterium Xanthomonas pruni utilizes the classic "tryptophan pathway" to synthesize nicotinic acid (Wilson and Henderson, J. Bacteriol. 85:221, 1963), evidence is accumulating that most bacteria do not exhibit a tryptophan-nicotinic acid relationship. The absence of such a relationship in Escherichia coli and Bacillus subtilis was reported by Yanofsky (J. Bacteriol. 68:577, 1954). ...

Activation of protein kinase C (PKC) stimulates nicotine-induced catecholamine secretion. PKC down-regulation by prolonged pretreatment with phorbol 12-myristate 13-acetate diminished nicotine-induced catecholamine secretion only slightly (approximately 16%), suggesting substantial PKC independence of nicotinic receptor activation. However, we found that bisindolylmaleimide compounds (which are...

The suppression of rat growth observed by several investigators (l-4), who have supplemented 9 per cent casein-sucrose diets with tryptophandeficient proteins or their derivatives, has been traced to the amino acids these preparations provide (4-6). Specifically, threonine, phenylalanine, and cystine or methionine have been shown to be involved (7-9). Since 9 per cent casein provides marginal a...

Koser, Breslove, and Doirfman (1941) obtained moderate growth (one billion cells per ml) of the three species, Brucella melitensis, Brucella abortus, and Brucella suis, in a chemically defined medium consisting of 17 amino acids, glucose, inorganic salts, thiamin, nicotinamide, biotin, and pantothenic acid. All of the strains studied required thiamin and nicotinamide, and all weere stimulated b...

The suppression of rat growth observed by several investigators (l-4), who have supplemented 9 per cent casein-sucrose diets with tryptophandeficient proteins or their derivatives, has been traced to the amino acids these preparations provide (4-6). Specifically, threonine, phenylalanine, and cystine or methionine have been shown to be involved (7-9). Since 9 per cent casein provides marginal a...

Mechanisms regulating CYP4F genes remain under investigation, although characterization of CYP4F regulatory modalities would facilitate the discovery of new drug targets. This present study shows that all-trans- and 9-cis-retinoic acids can inhibit CYP4F11 expression in human keratinocyte-derived HaCaT cells. Transrepression of many genes by retinoic acids is mediated by interactions between re...