Effect of aspirin and vitamins C and E on synovial rheumatoid arthritic and other cells.

Normal and rheumatoid arthritic human synovial cells, normal rat muscle and bone cells, were cultured with combinations of aspirin (acetylsalicytic acid), vitamins C and E. Aspirin reduced percent growth of all cells by about 1/5 relative to controls. High vitamin C eradicated arthritic cells. In combinations, vitamin C was most important in eradicating arthritic cells. A low-vitamin C combination was most effective in reducing arthritic cell populations, while having little effect on normal cells. Vitamin E retarded but did not prevent the action of vitamin C.     

Maternal vitamin A restriction alters biochemical development of the brain in rats.

The biochemical development of the fetal brain in relation to maternal vitamin A restriction was studied in rats. The vitamin A status of pregnant rats was varied by supplying low, medium and adequate amounts (6, 40, and 100 micrograms retinol/day/kg body weight, respectively) of vitamin A during pregnancy and suckling. The maternal vitamin A restriction caused an altered brain development in terms of tissue weight, DNA, RNA and protein levels, and biosynthesis of DNA and protein from [3H]-thymidine and [3H]-leucine, respectively. A dose-dependent effect of maternal vitamin A restriction on the metabolism of DNA, RNA and protein was noticed in the developing fetal brain of rats.     

Effect of aspirin and vitamins C and E on synovial rheumatoid arthritic and other cells

Summary Normal and rheumatoid arthritic human synovial cells, normal rat muscle and bone cells, were cultured with combinations of aspirin (acetylsalicytic acid), vitamins C and E. Aspirin reduced percent growth of all cells by about 1/5 relative to controls. High vitamin C eradicated arthritic cells. In combinations, vitamin C was most important in eradicating arthritic cells. A low-aspirin, low-vitamin C combination was most effective in reducing arthritic cell populations, while having little effect on normal cells. Vitamin E retarded but did not prevent the action of vitamin C.Acknowledgment. This work was supported by NRC grant No. A 6445 to Dr Bhakthan, Department of Kinesiology, Simon Fraser University.     

Local action of vitamin A on amphibian limb regeneration

Summary Axolotl forearms isolated from upper arm tissue either surgically or by local irradiation regenerate excessive structures after vitamin A treatment. This demonstration excludes the possibility of regeneration being altered by enhanced cellular migration and thus indicates that vitamin A respecifies cells close to the site of amputation.     

Effect of vitamin A on tumor development in burned, unburned, and glucocorticoid-treated mice inoculated with an oncogenic virus.

High doses of vitamin A decreased the severity of tumor development in mice inoculated with a murine sarcoma virus; the same doses of vitamin A had no effect on the increased tumorigenesis seen in animals severely stressed with thermal injury or the increased tumorigenesis induced by exogenous glucocorticoid administration.     

Maternal vitamin A restriction alters biochemical development of the brain in rats

Summary The biochemical development of the fetal brain in relation to maternal vitamin A restriction was studied in rats. The vitamin A status of pregnant rats was varied by supplying low, medium and adequate amounts (6, 40, and 100 g retinol/day/kg body weight, respectively) of vitamin A during pregnancy and suckling. The maternal vitamin A restriction caused an altered brain development in terms of tissue weight, DNA, RNA and protein levels, and biosynthesis of DNA and protein from [³H]-thymidine and [³H]-leucine, respectively. A dose-dependent effect of maternal vitamin A restriction on the metabolism of DNA, RNA and protein was noticed in the developing fetal brain of rats.     

The effects of vitamin A nutritional status on glutathione levels and microsomal lipid peroxidation in rat lung

In vitamin A-deficient rats, the glutathione level in lung was diminished and microsomal lipid peroxidation much increased. In vitamin A-loaded animals, however, both were depressed below control. Thus vitamin A protection against lipid peroxidation is independent of glutathione.     

Vitamin C and the immune response.

The inclusion of vitamin C in the drinking water of BALB/c mice was without effect on the humoral antibody response to sheep red blood cells and bacterial lipopolysaccharide. However, there was a significantly increased cell-mediated immune response as determined by increased T-lymphocyte responses to concanavalin A. This might suggest a mechanism, along with interferon enhancement, for the possible protection by vitamin C against some viral infections.     

Vitamin C and the immune response

Summary The inclusion of vitamin C in the drinking water of BALB/c mice was without effect on the humoral antibody response to sheep red blood cells and bacterial lipopolysaccharide. However, there was a significantly increased cell-mediated immune response as determined by increased T-lymphocyte responses to concanavalin A. This might suggest a mechanism, along with interferon enhancement, for the possible protection by vitamin C against some viral infections.We thank Miss Wendy Treat for excellent technical assistance.     

Activity of phospholipases A and some lysosomal enzymes in rat testes at different stages of hypervitaminosis A

Summary Excess of vitamin A induces decrease of neutral phospholipase A₁ and A₂ activity in rat testes homogenates on the 4th day, and increase of -galactosidase activity on the 8th day of treatment. It is suggested that phospholipase A activity decrease is of great importance in development of testicular disorders, caused by disbalance of vitamin A.     

Action des différentes formes actives de la vitamine A sur le mécanisme immunitaire chez le rat

Summary In this work, we have studied the role of different active forms of vitamin A considered as adjuvant of the immune mechanism in the rat. We also pointed out the adjuvant effect of retinol and retinal in comparison with the other active components of that vitamin with the bovine -globulin which is not an immunogenic antigen in itself in the control rat. Despite the fact that vitamin A has no antigenecity, it still possess an extrinsic adjuvanticity in presence of bovine -globulin. The degree of the immune response is increased.

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Action des différentes formes actives de la vitamine A sur le mécanisme immunitaire chez le rat

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Supporté par le C.N.R.S., Liban.     

Plasma and hepatic antioxidant control and vitamin A nutritional status

Twenty-seven rats were divided into three groups and fed on diets containing 0.3, 6 or 60 RE (retinol equivalent) retinyl palmitate/g food. After 7 weeks, hepatic vitamin A uptake was found to be more efficient in vitamin A-deficient rats than in rats given adequate vitamin A. We showed that during the metabolic adaptation of the animals to the level of vitamin A in the diet, extensive modifications occur in the antioxidant defences of the organism. In parallel with the increase in the level of vitamin A, the decrease in the level of -tocopherol in the plasma can bring about a greater susceptibility of the lipoproteins to oxidative stress. Similarly, the decrease in the hepatic -tocopherol level and in glutathione peroxidase activity leads to the weakening of the liver's antioxidant defences.     

The effects of vitamin A nutritional status on glutathione levels and microsomal lipid peroxidation in rat lung

Summary In vitamin A-deficient rats, the glutathione level in lung was diminished and microsomal lipid peroxidation much increased. In vitamin A-loaded animals, however, both were depressed below control. Thus vitamin A protection against lipid peroxidation is independent of glutathione.Acknowledgments. We thank Dr L. Y. Y. Fong and Mr David Y. H. Woo for preparing the animals used in this research, for retinol determinations and for valuable discussions, and also the China Medical Board of New York and the University of Hong Kong for the award of a Fellowship to V.P.     

Joint effects of dietary protein levels and vitamin A additions on the induction of cytochrome P450 by DDT in rats]

A 5 P. 100 level of protein from casein in a diet does not allow vitamin A to modify significantly induction of cytochrome P 450 on the Rat receiving or not receiving DDT. When the protein increases to a 15 p. 100 level, the induction is better providing vitamin A is to be given. If protein and vitamin A are necessary for cytochrom P 450 induction, an increase of protein level remains inefficient without vitamin A.     

Photoperiodic induction of diapause in an insect is vitamin A dependent

Summary A photoperiodic response was found to be absent in larvae of the parasitoid waspApanteles glomeratus when its host (caterpillars ofPieris brassicae) was reared on a low-carotenoid artificial diet. Addition of vitamin A to the host's diet restored the response to short-day photoperiods in the wasp larvae, thus showing that vitamin A is essential for photoperiodic induction of diapause. Possibly vitamin A or a derivative of vitamin A functions as the photoreceptor pigment for the photoperiodic reaction in this species of insect.     

Lack of influence of vitamin D deficiency on insulin release from the isolated pancreatic islets of rats

Pancreatic islets were isolated from young (100 g) and adult (390 g), normal and vitamin D deficient male Sprague-Dawley rats. The release of insulin from leucine-stimulated or glucose-stimulated islet was not altered by vitamin D deficiency. The in vitro addition of either 25-hydroxy- or 1,25-dihydroxyvitamin-D had no effect on insulin release from either normal or vitamin D deficient islets. We conclude that the earlier report (Normal et al., Science 209 (1980) 823-825) on vitamin D deficiency depressing insulin secretion from the perfused pancreas must be related to the vitamin's effect on insulin synthesis and not the islet's release of insulin.     

Liver vitamin A stores in chronic alcoholism in rats: effect of propylthiouracil treatment

Administration of alcohol to rats through drinking water for 8 weeks produced a significant decrease in the liver vitamin A stores without causing any change in the plasma vitamin A levels. Treatment of the alcoholic rats with propylthiouracil for 2 weeks restored the liver vitamin A reserves to control levels.     

Liver vitamin A stores in chronic alcoholism in rats: Effect of propylthiouracil treatment

Summary Administration of alcohol to rats through drinking water for 8 weeks produced a significant decrease in the liver vitamin A stores without causing any change in the plasma vitamin A levels. Treatment of the alcoholic rats with propylthiouracil for 2 weeks restored the liver vitamin A reserves to control levels.     

From carrot to clinic: an overview of the retinoic acid signaling pathway

Vitamin A is essential for the formation and maintenance of many body tissues. It is also important for embryonic growth and development and can act as a teratogen at critical periods of development. Retinoic acid (RA) is the biologically active form of vitamin A and its signaling is mediated by the RA and retinoid X receptors. In addition to its role as an important molecule during development, RA has also been implicated in clinical applications, both as a potential anti-tumor agent as well as for the treatment of skin diseases. This review presents an overview of how dietary retinoids are converted to RA, hence presenting the major players in RA metabolism and signaling, and highlights examples of treatment applications of retinoids. Moreover, we discuss the origin and diversification of the retinoid pathway, which are important factors for understanding the evolution of ligand-specificity among retinoid receptors.