In plants, γ-aminobutyric acid (GABA) is synthesized by polyamine degradation pathway besides GABA shunt. Aminoguanidine (AG) is a specific inhibitor of the key enzyme (diamine oxidase, DAO) for GABA formation in polyamine degradation pathway. In this study, AG was applied to study the functions of polyamine degradation pathway on growth and GABA accumulation in germinating fava bean under hypo...

The administration to rats of putrescine (750 mumol/kg body wt.) caused in liver, kidney and heart an increase in putrescine at 1 h and in diamine oxidase (EC 1.4.3.6) activity within 3-6 h. An increase in spermidine was observed at 9 h in liver and at 6 h in kidney, whereas in heart there was no change. The increase in diamine oxidase activity by exogenous putrescine was prevented by the admin...

Interest in polyamine catabolism has increased since it has been directly associated with the cytotoxic response of multiple tumour types to exposure to specific anti-tumour polyamine analogues. Human polyamine catabolism was considered to be a two-step pathway regulated by the rate-limiting enzyme spermidine/spermine N(1)-acetyltransferase (SSAT) that provides substrate for an acetylpolyamine ...

Human cells depleted of the naturally occurring polyamines putrescine, spermidine, and spermine exhibit altered chromatin structure and marked deficiencies in DNA replicative and repair processes. Similar effects have been observed following treatment of normal mammalian cells with various heavy metal salts. In an attempt to better understand how metals interfere with normal DNA metabolic proce...

(Changes in polyamines associated with zygotic embryogenesis in the Brazilian pine, Araucaria angustifolia (Bert.) O. Ktze.). Changes in the polyamine content were analyzed in different embryo developmental stages and tissues during seed development in the conifer Araucaria angustifolia (Bert.) O. Ktze. Free polyamine contents varied according to the tissue and stage of embryo development, the ...

Because intracellular polyamines have a critical role in cell proliferation and death pathways, the polyamine metabolic pathway represents a potential target for intervention in cancers. A number of polyamine analogues have been identified that downregulate polyamine synthesis and enhance polyamine catabolism, thereby depleting intracellular polyamines. Treatment of human breast cancer cell lin...

The natural polyamines are ubiquitous multifunctional organic cations which play important roles in regulating cellular proliferation and survival. Here we present a novel approach to investigating polyamine functions by using optical isomers of MeSpd (alpha-methylspermidine) and Me2Spm (alpha,omega-bismethylspermine), metabolically stable functional mimetics of natural polyamines. We studied t...

1) A rapid and high sensitive method for quantitation of free amino acids and poly-. amines in human erythrocytes using high performance liquid chromatography (HPLC) was devised by the author and his colleagues. 2) Measurement of free amino acids in erythrocytes was performed on 12 patients on our ward. Marked change in amino acid pattern was observed, and there are 2 in whom the prognosis of d...

Polyamines are ubiquitous organic cations of low molecular weight. The content of these amines is closely regulated by the cell according to the state of growth. The reactions responsible for the biosynthesis and interconversion of the polyamines and their precursor putrescine are described and the means by which polyamine content can be varied in response to exogenous stimuli are discussed. Th...

We have compared the effects of treatment with each of three bis(ethyl)polyamine analogues on a human small cell lung carcinoma (SCLC) line, NCI H82, and a non-small cell line, NCI H157, an undifferentiated large cell lung carcinoma. The bis(ethyl)polyamines have been shown to interfere with polyamine metabolism, presumably by regulation of the polyamine biosynthetic pathway in a manner similar...