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Results for “NICOTINIC ACID”

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PubMed1982

[Influence of a Pentifylline-Nicotinic Acid Combination on Vigilance and Mental Performance (author's transl)].

The effect of a single dose of 4 sugar-coated tablets of Cosaldon (1-hexyl-3,7-dimethylxanthine (pentifylline) + nicotinic acid) was shown by quantitative pharmaco-EEG investigations and psychometric tests in 12 volunteers aged 58 to 75 years, who were in a good physical condition. The design was randomized, double-blind and cross-over designed against placebo. EEG and psychometric tests were made before medication and repeated each hour up to 6 h after medication. Each turn was split up into a resting-EEG (R-EEG) and a vigilance-EEG (V-EEG) lasting 3 min each; the psychometric tests were made immediately afterwards. An increase of the vigilance, shown by an increased EEG-power, was found after Cosaldon administration as compared to placebo. Furthermore, the delta and theta intensity decreased to a statistically significant degree, while the intensity within the alpha-1-scope increased. The strongest effect as compared to placebo could be observed 4 h after medication. The statistical significance was shown for the V-EEG-condition, the R-EEG showed only minor changes. The effects in the occipital region were stronger than in the more frontal parts. In accordance with the results of the EEG, the psychological tests showed remarkable improvements in performance which reached their maximum between 2 and 4 h after medication.

Aged↗
PubMed1985

[Interaction of functionally coupled vitamins in the distribution and metabolism of [14C]nicotinic acid in tissues and blood cells].

Leucocytes adsorb by two orders of magnitude more labeled nicotinic acid ([14C]Na) than erythrocytes (as calculated on a per cell basis). The dynamics of binding of labeled vitamin by leucocytes is biphasic with the formation of predominantly [14C]nicotinic coenzymes already at very short time intervals after their injection to rats. Simultaneous injections of thiamine, riboflavin, lipoate and pantotenate increased the level of total labeled nicotinate metabolites in the blood and leucocytes 2.1- and 4.1-fold, respectively. The metabolism of subcutaneously injected [14C]NA was predominantly localized in the digestive system with a markedly pronounced two-phase dynamics of changes of the level of total labeled metabolites in the liver and small intestine concomitant with their secretion together with digestive juices. The functionally coupled vitamins injected simultaneously sharply increased the incorporation of the total label into liver tissues (up to 45% of the injected dose against 33% in the control) and the increase in the level of [14C]pyridine nucleotides. Similar effects were observed upon accumulation of labeled metabolites of [14C]NA in small intestine membranes. The increase in the maximal accumulation of nicotinate under effects of other group B vitamins in brain, heart and spleen tissues correlated with the dynamics, of their accumulation in the blood. In the postmaximal period in cardiac muscle and brain tissues, the second increase in the [14C]NA binding correlated with the dynamics of its accumulation in the digestive system.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Effects of nicotinic acid and its derivatives on lipid metabolism and other metabolic factors related to atherosclerosis.

Nicotinic acid treatment thus induces several beneficial effects on serum lipoproteins and on hemodynamic factors related to the risk for development of atherosclerosis. It effectively reduces the atherogenic lipoproteins VLDL and LDL and also increases the anti-atherogenic HDL, mainly the HDL2 fraction. The drug seems to be active not only in decreasing the synthesis of various lipoproteins but also to enhance the removal into peripheral tissues, thereby speeding up the catabolic events of serum lipoproteins. The mode of action of NAc in adipose and muscle tissue needs further evaluation to better understand the complex interplay between free fatty acid and glucose and insulin metabolism. The recent findings of a stimulation of prostacyclin formation as well as a reduction in platelet aggregation are newly discovered favorable effects of the drug that needs to be further examined. Although the drug seems to induce some undesirable side effects (reversible), its several favorable anti-atherosclerotic properties should stimulate both experimental and clinical research with this drug. Hopefully newer derivatives with even better tolerance may be developed.

Animals↗
PubMed2002

Niacin (nicotinic acid) in non-physiological doses causes hyperhomocysteineaemia in Sprague-Dawley rats.

Niacin (nicotinic acid) in its non-physiological dose level is known to be an effective lipid-lowering agent; its potential risk as a therapeutic agent, however, has not been critically considered. Since niacin is excreted predominantly as methylated pyridones, requiring methionine as a methyl donor, the present study was undertaken to examine whether metabolism of the amino acid is altered in the presence of large doses of niacin. Male Sprague-Dawley rats were given a nutritionally adequate, semi-synthetic diet containing niacin at a level of either 400 or 1000mg/kg diet (compared to 30mg/kg in the control diet) for up to 3 months. Supplementation with niacin (1,000 mg/kg diet) for 3 months resulted in a significant increase in plasma and urinary total homocysteine levels; this increase was further accentuated in the presence of a high methionine diet. The hyperhomocysteineaemia was accompanied by a significant decrease in plasma concentrations of vitamins B6 and B12, which are cofactors for the metabolism of homocysteine. The homocysteine-raising action of niacin, in particular, has an important toxicological implication, as hyperhomocysteineaemia is considered to be an independent risk factor for arterial occlusive disease. The niacin-associated change in homocysteine status may be an important limiting factor in the use of this vitamin as a lipid-lowering agent.

Animals↗
PubMed2002

Nicotinic acid adenine dinucleotide phosphate (NAADP) is present at micromolar concentrations in sea urchin spermatozoa.

Nicotinic acid adenine dinucleotide phosphate (NAADP) has been shown to induce Ca(2+) release in numerous cellular models, ranging from marine invertebrates to mammals. However, endogenous levels of this pyridine dinucleotide have yet to be demonstrated. In the sea urchin egg, NAADP receptors are abundant but have the peculiarity of being inactivated at low concentrations (picomolar) and activated at higher concentrations (nanomolar) which apparently rules out any possibility of the receptor being activated by concentration rises induced by a slow enzymatic formation in the cytosol. One of the most important events of fertilization is a Ca(2+) transient in the egg, which leads to egg activation. The mechanisms which underlie the transient are still unclear and several theories persist including the existence of a sperm receptor and that soluble factors may pass from the sperm to the egg cytosol. We have investigated the possibility that NAADP might be present in sperm. Indeed, we found that sea water-activated spermatozoa are able to synthesize NAADP and that sperm extracts contain micromolar concentrations of the messenger. Although it is unlikely that NAADP alone mediates the fertilization wave, our data suggest that transfer of NAADP from spermatozoa to egg may play a role in this phenomenon.

Animals↗
PubMed1982

[Treatment of patients with neurologic syndromes of cervical osteochondrosis by electrophoresis of papaverine and nicotinic acid using sinusoidally-modulated and diadynamic currents].

The authors describe the time course of some biochemical and hemodynamic parameters in patients suffering from cervical osteochondrosis with neurological symptoms treated by electrophoresis of papaverine and nicotinic acid with sinusoidal modulated and diadynamic currents. Under treatment there were 124 patients aged 16 to 76 years. The electrophoresis was performed by the method developed by the authors. All the patients showed a reduction of the prothrombine, cholesterol and beta-lipoproteid levels and a rise of the lecithine-cholesterol index. This pointed to a favourable effect of the treatment on lipid metabolism. An improvement of some central hemodynamic parameters and of peripheral circulation in the zone of the forearms was also noted.

Administration, Oral↗