Polyamines are plant growth regulators distributed among all plant species. The major polyamines are diamine putrescine, triamine spermidine and tetraamine spermine. Polyamines are involved in a number of growth and developmental processes, as well as in plant responses to a variety of unfavorable factors. Polyamines can stabilize cell constituents and protect macromolecules from free radicals ...

The total cellular mass of the small intestine is well controlled and can adapt, with hypo- or hyperplasia, to a wide variety of stimuli. Luminal nutrients, hormonal factors and pancreatic and biliary secretions have all been implicated in the regulation of intestinal mucosal growth. The polyamines (putrescine, spermidine and spermine) and the key enzyme controlling their synthesis (ornithine d...

Transformed baby-hamster-kidney cells contain higher intracellular concentrations of polyamines than do normal cells. The difference is greater in high-density confluent cultures. Transformed cells incorporate exogenous putrescine into the cells at a faster rate than do normal cells. They also show a marked increase in the rate of spermine biosynthesis compared with normal cells. Transformed ce...

The action of exogenous polyamines (putrescine, spermidine, and spermine) on ;washing' and fusicoccin-stimulated K(+) uptake and H(+) extrusion through the plasmamembrane in maize (Zea mays L., hybrid line Plenus S 516) root apical segments was studied. The results showed that polyamines inhibit the washing-stimulated K(+) influx and H(+) extrusion without interfering with K(+) uptake and H(+) ...

1 Gilad G, Gilad V. Polyamines in neurotrauma. Ubiquitous molecules in search of a function. Biochem Phannacol 1992;44:401-7. 2 Shohami E, Nates JL, Glantz L, et al. Changes in brain polyamine concentrations following head injury. Exp Neurol 1992;117:189-95. 3 Koski P, Helander IM, Sarvas M, Vaara M. Analysis of polyamines as their dabsyl derivatives by reversed phase high performance liquid ch...

1 Gilad G, Gilad V. Polyamines in neurotrauma. Ubiquitous molecules in search of a function. Biochem Phannacol 1992;44:401-7. 2 Shohami E, Nates JL, Glantz L, et al. Changes in brain polyamine concentrations following head injury. Exp Neurol 1992;117:189-95. 3 Koski P, Helander IM, Sarvas M, Vaara M. Analysis of polyamines as their dabsyl derivatives by reversed phase high performance liquid ch...

Sensing and responding to environmental cues is a fundamental characteristic of bacterial physiology and virulence. Here we identify polyamines as novel environmental signals essential for virulence of Salmonella enterica serovar Typhimurium, a major intracellular pathogen and a model organism for studying typhoid fever. Central to its virulence are two major virulence loci Salmonella Pathogeni...

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...

Polyamines are organic polycations that have been associated with a large number of plant growth and developmental processes, such as pollination and fruit set. Most of the research has been done in horticultural plants, with only limited information existing for cotton. Numerous studies have correlated increased fruit set with increased polyamines concentration during flowering. Therefore in t...

This study was conducted to evaluate the effects of exogenous polyamines, isopropyl ester, 2, 4-D and naphthalene acetamide application on yield and quality of date palm of ‘Kabkab’ cultivar. The inflorescences sprayed with 2, 4-D isopropylester (0, 10, and 20 mg L-1), naphthalene acetamide (0, 80, and 120 mg L-1), putrescence and spermidine (0, 0.1, and 1.0 mM), three or six weeks after pollin...