BACKGROUND/AIMS Studies performed in experimental animals have shown that polyamines contribute to several physiological and pathological processes, including cardiac hypertrophy. This involves an increase in ornithine decarboxylase (ODC) activity and intracellular polyamines associated with regulation of gene expression. Difluoromethylornithine (DFMO), an irreversible inhibitor of ODC, has att...

The polyamines putrescine, spermidine, and spermine have been implicated in the regulation of cell proliferation and differentiation. Previous studies, however, have demonstrated that the polyamines are essential for proliferation, but not differentiation, of HL-60 human promyelocytic leukemia cells. We have extended these findings by demonstrating a highly significant relationship between intr...

Phosphatidylinosital-4,5-bisphosphate (PIP2) acts as an essential factor regulating the activity of all Kir channels. In most Kir members, the dependence on PIP2 is modulated by other factors, such as protein kinases (in Kir1), G(betagamma) (in Kir3), and the sulfonylurea receptor (in Kir6). So far, however, no regulator has been identified in Kir2 channels. Here we show that polyamines, which ...

Asthma is a complex disease of airways, where the interactions of immune and structural cells result in disease outcomes with airway remodeling and airway hyper-responsiveness. Polyamines, which are small-sized, natural super-cations, interact with negatively charged intracellular macromolecules, and altered levels of polyamines and their interactions have been associated with different patholo...

Polyamines are unique polycationic metabolites, controlling a variety of vital functions in plants, including growth and stress responses. Over the last two decades a bulk of data was accumulated providing explicit evidence that polyamines play an essential role in regulating plant membrane transport. The most straightforward example is a blockage of the two major vacuolar cation channels, name...

It was previously reported that bacteriophage T4 contains the polyamines putrescine, NH2(CH2)$;IH2, and spermidine, NHQ(CH&NH(CH&NH2, in amounts sufficient to neutralize about half of the viral deoxyribonucleic acid (1). The putrescine and spermidine in the phage were found to be derived from the large amount of these polyamines normally present in the host bacterium, Escherichia coli B. It was...

The naturally occurring polyamines putrescine, spermidine, and spermine are involved in signal transduction. This has been demonstrated by using inhibitors for polyamine biosynthesis (such as alpha-difluoromethylornithine) or adding polyamines to cultured cells. Different polyamines, preferentially activated protein kinases (tyrosine kinases and MAP kinases), stimulated the expression of nuclea...

The incorporation of l-[(14)C]ornithine and [(14)C]putrescine into putrescine, spermidine, and spermine in type 5 adenovirus-infected KB cells was identical to that in uninfected control cells early in infection, but incorporation into putrescine stopped after 8 to 12 h and the rate of incorporation into spermidine was reduced between 12 and 20 h after infection. The amount of polyamines found ...

Polyamines are polycations that interact with negatively charged molecules such as DNA, RNA and proteins. They play multiple roles in cell growth, survival and proliferation. Changes in polyamine levels have been associated with aging and diseases. Their levels decline continuously with age and polyamine (spermidine or high-polyamine diet) supplementation increases life span in model organisms....