Polyamines block the retinal cyclic nucleotide-gated channel from both the intracellular and extracellular sides. The voltage-dependent mechanism by which intracellular polyamines inhibit the channel current is complex: as membrane voltage is increased in the presence of polyamines, current inhibition is not monotonic, but exhibits a pronounced damped undulation. To understand the blocking mech...

Physiological polyamines are ubiquitous polycations with pleiotropic biochemical activities, including regulation of gene expression, cell proliferation and modulation of cell signalling. Reports that the polyamines with cytoprotective activities were induced by diverse stresses raised the hypothesis that physiological polyamines may play a role in inducing stress response. In a wide range of o...

Polyamines, such as putrescine, spermidine and spermine, have indirectly been linked with the regulation of gene expression, and their concentrations are typically increased in cancer cells. Although effects on transcription factor binding to cognate DNA targets have been demonstrated, the mechanisms of the biological action of polyamines is poorly understood. Employing uranyl photo-probing we ...

Polyamines are closely related to many aspects of cell growth. Since increased amounts of polyamines in the urine of human cancer patients were reported in 1971, polyamines have been studied from the standpoint of tumor markers. In this study, polyamines in erythrocytes, plasma and urine were determined in 42 controls and 105 patients with gynecologic malignant tumors. The changes in polyamine ...

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...

PEGG, ANTHONY E., AND PETER P. MCCANN. PoZyamine metabohsm and function. Am. J. Physiol. 243 (Cell Physiol. 12): C212-C221, 1982.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 p...

Two cultivars contrasting in NaCl tolerance were used to investigate the possible involvement of polyamines in salt tolerant mechanisms in roots of vegetable soybean. ‘Tianfeng’, the salt tolerant cultivar exhibited overall higher contents of free, soluble conjugated and insoluble bound forms of polyamines (putrescine, spermidine and spermine) except for free spermidine over the salt sensitive ...

The balance between accumulation of stress-induced polyamines and reactive oxygen species (ROS) is arguably a critical factor in plant tolerance to salt stress. Polyamines are compounds, which accumulate in plants under salt stress and help maintain cellular ROS homeostasis. In this review we first outline the role of polyamines in mediating salt stress responses through their modulation of red...

Polyamines--putrescine, spermidine, and spermine--are ubiquitous cellular components that play an important role in cell growth and differentiation. Using A431 cells, a cell line that overexpresses the epidermal growth factor (EGF) receptor, we found that polyamines modulate EGF-mediated growth inhibition. The natural polyamine, putrescine, was the most effective, followed by diamines containin...

The polyamines are low molecular mass aliphatic amines that can be synthesized by both prokaryotic and eukaryotic cells. The most common are putrescine, spermidhe and spermine (Fig. I ). The intracellular concentrations of these polyamines vary greatly with the proliferative status of the cell, and also in response to a wide variety of stimuli [ 1-31, Induction of polyamine biosynthesis, a deli...