The polyamines putrescine, spermidine and spermine are essential for cell renewal and, therefore, are needed to keep the body healthy. It was previously believed that polyamines are synthesized by every cell in the body when required. However, in the present paper evidence is provided to show that, as in the case of the essential amino acids, the diet can supply sufficient amounts of polyamines...

Polyamines are essential for embryonic and fetal survival, growth, and development. Additionally, polyamines may induce autophagy in mammalian cells. However, little is known about the availability of polyamines or autophagy in the porcine conceptus with intrauterine growth restriction (IUGR). The present study was performed to evaluate the developmental changes of polyamine concentrations in I...

The ubiquitous polyamines fulfil a variety of functions in all three kingdoms of life. However, little is known about the biosynthesis of these compounds in Gram-positive bacteria. We show that, in Bacillus subtilis, there is a single pathway to polyamines, starting from arginine, with agmatine as an intermediate. We first identified the structural gene of arginine decarboxylase, speA (formerly...

Floating ferns of the genus Azolla detach their roots under stress conditions, a unique adaptive response termed rapid root abscission. We found that Azolla pinnata plants exhibited dose-dependent rapid root abscission in response to the polyamines spermidine and spermine after a substantial time lag (>20 min). The duration of the time lag decreased in response to high pH and high temperature w...

The polyamines have been under active investigation for nearly three decades. There is a great deal of evidence that they play an important role in gastrointestinal mucosal growth, but the mechanisms through which this role is carried out are still not fully explained. This review examines the role of the polyamines in the regulation of mucosal growth, the control of intracellular polyamine lev...

Polyamines downregulate immune reactivity. RA is associated with decreased IL 2 production. In this study, we present evidence to suggest that excessive polyamines can contribute to the IL 2 deficiency in RA. Blocking polyamine production with inhibitors of ornithine decarboxylase results in increased IL 2 production by RA PBMC. Moreover, polyamine oxidase (PAO) inhibitors and catalase also inc...

Addition of the polyamines spermidine, spermine, or putrescine to a fractionated mammalian cell-free protein-synthesis system programmed by a variety of mRNAs results in a 3- to 5-fold stimulation of amino acid incorporation over that found in the absence of added polyamine. The mRNAs used as template were adenovirus mRNA, globin 9s mRNA, and RNA from the bacteriophages R17, Qbeta, and MS2. The...

When rat liver nuclei prepared with polyamines as stabilising cations are digested with DNAase II, release of both inactive chromatin and Mg-soluble, active chromatin is greatly reduced, in comparison to digestion of liver nuclei prepared with Mg2+ as stabilising cation. Chromatin release from polyamine stabilised nuclei is also inhibited relative to Mg-stabilised nuclei following digestion wit...

Vibrio cholerae is the causative agent of the severe enteric disease cholera. To cause cholera the bacterium must be able to synthesize both cholera toxin (CT) and toxin-coregulated pilus (TCP) which mediates autoagglutination and is required for colonization of the small intestine. Only a few environmental signals have been shown to regulate V. cholerae virulence gene expression. Polyamines, w...

PURPOSE To investigate the involvement of polyamines (putrescine, spermidine, and spermine) in the proliferation of retinal pigment epithelium (RPE) using cultured bovine RPE cells. METHODS The polyamine content and the activities of rate-limiting enzymes in polyamine biosynthesis (ornithine decarboxylase [ODC] and S-adenosylmethionine decarboxylase [SAMDC]) and in polyamine biodegradation (s...