Effect of Dietary Ornithine on Renal and Hepatic Polyamine Synthesis

Bedford, M.R.; Smith, T. K.; Summers, J. D.

doi:10.1159/000177462

Cited by 13 publications

(5 citation statements)

References 12 publications

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“…The lack of ability of the increased he patic concentration of ornithine to result in increased polyamine concentrations [13] is in contrast to that seen in the avian liver [ 18] and this supports the hypothesis that the presence of a functional urea cycle in ureotelic animals may limit the potential for pre cursor amino acids to promote polyamine synthesis.…”

Section: Discussionsupporting

confidence: 60%

Effects of Dietary Polyamine Precursors on the Metabolism and Tissue Concentrations of Amino Acids in the Rat

Smith¹,

Lindqvist²,

Alakuijala³

et al. 1989

Ann Nutr Metab

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Experiments were conducted to determine the effects of dietary supplements of amino acid precursors of polyamines on amino acid metabolism in the rat in order to better understand comparative aspects of polyamine metabolism. Rats were fed isonitrogenous combinations of methionine, ornithine, arginine and 2-difluoromethylornithine in casein-based diets. It was observed that hepatic concentrations of methionine, 5’-deoxy-5’-methylthioadenosine and decarboxylated S-adenosylmethionine were more easily influenced by diet than were arginine and metabolites. It was concluded that rats may be more refractory to exogenous polyamine precursor amino acids than are chicks because of the presence of a functional urea cycle.

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Section: Discussionsupporting

confidence: 60%

Effects of Dietary Polyamine Precursors on the Metabolism and Tissue Concentrations of Amino Acids in the Rat

Smith¹,

Lindqvist²,

Alakuijala³

et al. 1989

Ann Nutr Metab

Self Cite

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“…The properties of spermidine synthase and spermine synthase have not been fully clarified, however, they seem to lack a regulatory or rate-limiting role in polyamine synthesis. The administration of arginine or ornithine stimulates putrescine levels; however, the subsequent synthesis of polyamines is not necessarily stimulated in elderly people or aged animals [ 72 , 74 , 75 , 76 ]. These findings indicate that the activities of spermine and spermidine synthases decrease gradually with aging.…”

Section: Aging and Polyaminementioning

confidence: 99%

Overview of Polyamines as Nutrients for Human Healthy Long Life and Effect of Increased Polyamine Intake on DNA Methylation

Soda

2022

Cells

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Polyamines, spermidine and spermine, are synthesized in every living cell and are therefore contained in foods, especially in those that are thought to contribute to health and longevity. They have many physiological activities similar to those of antioxidant and anti-inflammatory substances such as polyphenols. These include antioxidant and anti-inflammatory properties, cell and gene protection, and autophagy activation. We have first reported that increased polyamine intake (spermidine much more so than spermine) over a long period increased blood spermine levels and inhibited aging-associated pathologies and pro-inflammatory status in humans and mice and extended life span of mice. However, it is unlikely that the life-extending effect of polyamines is exerted by the same bioactivity as polyphenols because most studies using polyphenols and antioxidants have failed to demonstrate their life-extending effects. Recent investigations revealed that aging-associated pathologies and lifespan are closely associated with DNA methylation, a regulatory mechanism of gene expression. There is a close relationship between polyamine metabolism and DNA methylation. We have shown that the changes in polyamine metabolism affect the concentrations of substances and enzyme activities involved in DNA methylation. I consider that the increased capability of regulation of DNA methylation by spermine is a key of healthy long life of humans.

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“…Although the properties of spermidine synthase and spermine synthase have not been fully clarified, they are considered to lack a regulatory or rate-limiting role in polyamine synthesis. The administration of arginine or ornithine stimulates putrescine levels; however, the subsequent synthesis of polyamines is not necessarily stimulated in elderly people or aged animals [ 67 , 69 , 70 , 71 ]. These findings indicate that the activities of spermine and spermidine synthases decrease gradually with aging.…”

Section: Polyaminesmentioning

confidence: 99%

Polyamine Metabolism and Gene Methylation in Conjunction with One-Carbon Metabolism

Soda

2018

IJMS

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Recent investigations have revealed that changes in DNA methylation status play an important role in aging-associated pathologies and lifespan. The methylation of DNA is regulated by DNA methyltransferases (DNMT1, DNMT3a, and DNMT3b) in the presence of S-adenosylmethionine (SAM), which serves as a methyl group donor. Increased availability of SAM enhances DNMT activity, while its metabolites, S-adenosyl-l-homocysteine (SAH) and decarboxylated S-adenosylmethionine (dcSAM), act to inhibit DNMT activity. SAH, which is converted from SAM by adding a methyl group to cytosine residues in DNA, is an intermediate precursor of homocysteine. dcSAM, converted from SAM by the enzymatic activity of adenosylmethionine decarboxylase, provides an aminopropyl group to synthesize the polyamines spermine and spermidine. Increased homocysteine levels are a significant risk factor for the development of a wide range of conditions, including cardiovascular diseases. However, successful homocysteine-lowering treatment by vitamins (B6, B12, and folate) failed to improve these conditions. Long-term increased polyamine intake elevated blood spermine levels and inhibited aging-associated pathologies in mice and humans. Spermine reversed changes (increased dcSAM, decreased DNMT activity, aberrant DNA methylation, and proinflammatory status) induced by the inhibition of ornithine decarboxylase. The relation between polyamine metabolism, one-carbon metabolism, DNA methylation, and the biological mechanism of spermine-induced lifespan extension is discussed.

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Effect of Dietary Ornithine on Renal and Hepatic Polyamine Synthesis

Cited by 13 publications

References 12 publications

Effects of Dietary Polyamine Precursors on the Metabolism and Tissue Concentrations of Amino Acids in the Rat

Effects of Dietary Polyamine Precursors on the Metabolism and Tissue Concentrations of Amino Acids in the Rat

Overview of Polyamines as Nutrients for Human Healthy Long Life and Effect of Increased Polyamine Intake on DNA Methylation

Polyamine Metabolism and Gene Methylation in Conjunction with One-Carbon Metabolism

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