RESUMO
Polyamines (Pas) are short molecules that exhibit two or three amine groups that are positively charged at a physiological pH. These small molecules are present in high concentrations in a wide variety of organisms and tissues, suggesting that they play an important role in cellular physiology. Polyamines include spermine, spermidine, and putrescine, which play important roles in age-related diseases that have not been completely elucidated. Aging is a natural process, defined as the time-related deterioration of the physiological functions; it is considered a risk factor for degenerative diseases such as cardiovascular, neurodegenerative, and musculoskeletal diseases; arthritis; and even cancer. In this review, we provide a new perspective on the participation of Pas in the cellular and molecular processes related to age-related diseases, focusing our attention on important degenerative diseases such as Alzheimerߣs disease, Parkinsonߣs disease, osteoarthritis, sarcopenia, and osteoporosis. This new perspective leads us to propose that Pas function as novel biomarkers for age-related diseases, with the main purpose of achieving new molecular alternatives for healthier aging.
Assuntos
Poliaminas , Espermidina , Espermina/fisiologia , PutrescinaRESUMO
Endogenous free polyamines (PAs), putrescine, spermidine and spermine, from developing fruitlets of Citrus species (Citrus unshiu Marc. and Citrus clementina Hort ex Tanaka) which differ in their parthenocarpic ability, and from uniflowered leafy and leafless inflorescences differing in their ability to set, have been determined by dansylation and separation of dansyl derivatives by HPLC. No significant differences in PAs content were observed between species or between leafy and leafless inflorescences which, nevertheless, significantly differed in fruit set. However, significant differences in their content were found in developing fruitlets, depending on the preceding flowering intensity of the tree and on the fruitlet load. These results suggest that, in Citrus, PAs may act as a nitrogen source rather than a regulator of fruit set.
Assuntos
Citrus/fisiologia , Frutas/crescimento & desenvolvimento , Putrescina/fisiologia , Sementes/fisiologia , Espermidina/fisiologia , Espermina/fisiologia , Citrus/crescimento & desenvolvimento , Flores/fisiologia , Folhas de Planta/fisiologia , Especificidade da EspécieRESUMO
1. The electric organ of Torpedo nobiliana contained putrescine (PUT), spermidine (SPD), spermine (SPM), and cadaverine (CAD). Traces of acetylated SPD and SPM were occasionaly seen. 2. Upon fractionation of the tissue by differential centrifugation, the polyamines (PA) were found predominantly in the soluble fraction. The postsynaptic membrane fraction, containing a high concentration of acetylcholine receptor (AChR), was proportionally enriched in SPM. The molar ratio of SPM to AChR was approximately two in these membranes. 3. The effect of exogeneous PA on AChR function was studied by two methods: carbamoylcholine (CCh)-dependent 86Rb+ influx into receptor-rich membrane vesicles and [alpha-125I]bungarotoxin (Bgt) binding to the AChR. 4. SPM inhibited both ion influx and the rate of Bgt binding at concentrations above 1 mM, and therefore it appears to act as a competitive antagonist of the AChR. 5. At submicromolar concentrations, and only after preincubation with the receptor-rich membrane, SPM and PUT increased the ion influx by about 20% over control values. 6. Preincubation with 100 nM SPM did not affect the equilibrium binding of iodinated toxin or the rate of toxin binding, and therefore SPM was not uncovering new receptors. 7. By measuring the initial rate of toxin binding after different periods of preincubation with 1 microM CCh, the rate of the slow phase of receptor desensitization was determined. This rate was not changed by 100 nM SPM. 8. Although these results suggest that at low concentrations SPM is a positive modulator of the AChR, the precise mechanism of action is not determined yet.
Assuntos
Órgão Elétrico/química , Poliaminas/isolamento & purificação , Receptores Colinérgicos/efeitos dos fármacos , Espermina/fisiologia , Torpedo/metabolismo , Animais , Ligação Competitiva , Bungarotoxinas/metabolismo , Bungarotoxinas/farmacologia , Carbacol/metabolismo , Carbacol/farmacologia , Membrana Celular/química , Poliaminas/metabolismo , Poliaminas/farmacologia , Receptores Colinérgicos/metabolismo , Rubídio/metabolismo , Espermina/isolamento & purificação , Espermina/metabolismo , Espermina/farmacologiaRESUMO
Han sido estudiados los resultados de 195 muestras de liquido seminal para la caracterizacion de bacterias, piocitos, leucocitos, globulos rojos y cristales de espermina. Los hallazgos en las preparaciones de semen han mostrado que el 93,84 por ciento contenian bacterias; 87,68 por ciento piocitos; el 57,47 por ciento leucocitos; el 27,69 por ciento globulos rojos y el 28,71 por ciento cristales de espermina. Estos elementos formes parecen identificar procesos infecciosos, en su mayoria cronicos, de la prostata y las vesiculas seminales. No se pudo descartar lesiones a nivel del conducto uretral. El hallazgo de cantidades significativas de globulos rojos en algunos pacientes permite presumir antecedentes bacilares (tuberculosis genital o urogenital). Del mismo modo, el hallazgo de cristales de espermina hace suponer lesiones prostaticas antiguas cuya importancia debera ser dilucidada.