Decreased plasmatic spermidine and increased spermine in mild cognitive impairment and Alzheimer's disease patients

Abstract Background Current evidence suggests that upregulation of polyamines system plays a role both in cognitive deficit and synaptic loss observed in Alzheimer's disease (AD). Objective The aim of this study was to determine the plasmatic concentration of polyamines in mild cognitive impairment (MCI) and AD patients in comparison with healthy controls (HC). Methods Plasmatic polyamines were quantified using the AbsoluteIDQ® p180 and liquid chromatography coupled to tandem mass spectrometry (LC/MS-MS). Results The study group comprised 34 AD patients, 20 MCI and 25 HC. All individuals were followed for 4 years. During this period 8 amnestic MCI patients (40% of the MCI sample at baseline) converted to AD. Spermidine level was lower in both patient groups (AD; MCI) compared to HC (p = 0.007). Plasma levels of spermine were higher in the MCI group (p < 0.001), but decreased in the sub-sample of MCI patients who converted to AD (p = 0.043). No statistically significant differences were found in ornithine and putrescine levels (p = 0.056 and p = 0.126, respectively). Discussion Our results suggest dynamic changes in the expression of polyamines in the MCI-AD continuum.

A useful procedure for detection of polyamines in biological samples as a potential diagnostic tool in cancer diagnosis

Background: Polyamines present in human body are frequently considered as markers of occurrence of cancer. Therefore, the availability of simple and efficient method for determination of their level in body liquids and tissues is of some interest. Methods: Supported liquid membrane technology coupled with HPLC seems to be an appropriate technique to follow the level of polyamines in human blood and urine. Thus, the membranes of two different geometries: flat sheet and hollow fiber were studied as a mean for separation and enrichment of studied polyamines from urine and tissue samples in order to prepare samples to be analyzed by HPLC. Conclusions: Developed extraction systems offer an interesting alternative to traditional techniques such as: liquid-liquid or solid-phase extraction due to several features, which are: very high enrichment of polyamines without previous work-up, simple procedure of extraction and tiny volume of organic solvents used. This enables efficient determination of their levels in body liquids (AU)

Teores de poliaminas em alguns alimentos da dieta básica do povo brasileiro / Polyamines contents in some foods from Brazilian population basic diet

Os teores de poliaminas variam, assim como a sua necessidade, por estarem relacionadas diretamente com o crescimento de células. Neste estudo, foram analisados os teores de putrescina, espermidina e espermina em diversos alimentos de origem vegetal e em ovos. O cozimento não afetou os teores em arroz ou feijão, porém em batata inglesa houve diferença, sendo que a fritura incrementou o teor principalmente de putrescina. Alface, laranja, banana e tomate apresentaram teores de putrescina maiores, enquanto que em cebola, alho, ovos, arroz e feijão houve predominância de espermidina e espermina. Estes resultados são relevantes para uma possível elaboração da dieta de muitas pessoas, dependendo da sua necessidade diária.

Intracellular polyamine pools, oligopeptide-binding protein A expression, and resistance to aminoglycosides in Escherichia coli

The role of intracellular free polyamine (putrescine and spermidine) pools in multiple resistance to aminoglycoside antibiotics was investigated among in vitro selected kanamycin-resistant Escherichia coli J53 mutants expressing diminished oligopeptide-binding protein (OppA) levels and/or defective ornithine decarboxylase (ODC) activity. The results suggest that diminished OppA content, but not defective ODC activity expression, increased the relative concentration of free spermidine as compared to the wild type strain. Moreover, by adding exogenous polyamines or polyamine synthesis inhibitors to cultures with different mutant strains, a direct relationship between the intracellular OppA levels and resistance to kanamycin was revealed. Collectively these results further suggest a complex relation among OppA expression, aminoglycoside resistance and polyamine metabolism.

Cambios en la actividad de arginasa pancreática en ratas púberes y adultas inducidos por la castración / Activity pancreatic arginase changes inducted by castration in pubescent and adult rats

La actividad de arginasa en riñón e intestino delgado en algunas especies de mamíferos es sensible a la castración, un hallazgo que puede sugerir su dependencia de testosterona. Sin embargo, hasta donde conocemos, la información sobre la regulación de la actividad de arginasa pancreática es escasa. En este trabajo se estudió el efecto de la orquidectomía sobre la actividad de arginasa pancreática en ratas púberes y adultas. Las ratas púberes y adultas, de 21 días y 4 meses de edad, respectivamente, fueron orquidectomizadas y sacrificadas a varios tiempos después de la cirugía. Grupos de ratas intactas sirvieron como controles. La actividad de arginasa y las proteínas fueron determinadas en tejido pancreático. En suero, la actividad de la enzima fue determinada en adición a la glucosa, los triglicéridos y las proteínas totales. En las ratas la actividad de arginasa pancreática y sérica mostró un pico el día 5 poscirugía, mientras que en las adultas, se observó un aumento en la actividad de arginina el día 20. Se observaron cambios en las proteínas séricas y pancreáticas en ratas púberes castradas, pero no en las adultas. Estos resultados sugieren que la arginasa pancreática es dependiente de andrógenos, y que hay diferencia de edades, probablemente debido a patrones distintos de secreción hormonal en ratas adultas y púberes.

Polyamines in the male reproductive system

This review covers some common aspects of the biosynthesis, interconversion pathways and biochemical functions of polyamines. A particular emphasis is given in experitemtal models as well as humans, to their presence in the male gonad, postate gland, seminal vesicles, epididymis and semen. The interaction between hormones (androgens, LH, FSH and PRL) and the main enzymes involved on the polymine biosynthesis, and the relationship of these compounds on cell growth and differentation, are also discussed. In this regard, an attention is offered to the potential role of polymines during early spermatogenesis stages and the use of some enzymed involved in their biosynthesis as sensitive and specific markers of the action of androgens and antiandrogens in the epididymis. Finally, a special issue is addressed to the controversial information documented on polymines, their oxidation products and the relationship with male fertility.