RESUMO
Acetoacetate (AA) is a ketone body, which generates reactive oxygen species (ROS). ROS production is impacted by the formation of covalent bonds between amino groups of biomacromolecules and reducing sugars (glycation). Glycation can damage DNA by causing strand breaks, mutations, and changes in gene expression. DNA damage could contribute to the pathogenesis of various diseases, including neurological disorders, complications of diabetes, and aging. Here we studied the enhancement of glucose-mediated DNA glycation by AA for the first time. The effect of AA on the structural changes, Amadori and advanced glycation end products (AGEs) formation of DNA incubated with glucose for 4 weeks were investigated using various techniques. These included UV-Vis, circular dichroism (CD) and fluorescence spectroscopy, and agarose gel electrophoresis. The results of UV-Vis and fluorescence spectroscopy confirmed that AA increased the DNA-AGE formation. The NBT test showed that AA also increased Amadori product formation of glycated DNA. Based on the CD and agarose gel electrophoresis results, the structural changes of glycated DNA was increased in the presence of AA. The chemiluminescence results indicated that AA increased ROS formation. Thus AA has an activator role in DNA glycation, which could enhance the adverse effects of glycation under high glucose conditions.
RESUMO
A simple, cheap and flexible flowcell based on a standard 5 mm NMR tube, designed for the monitoring of reactions but of wide applicability, is described. No modification of the NMR instrument is needed, allowing the system to be employed with any conventional NMR probe and magnet. The system is robust and economical in use of reagents, and can be used for studying both homogeneous and heterogeneous reactions.
Assuntos
Fenômenos Químicos , Espectroscopia de Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Desenho de Equipamento , Esterificação , Hidrólise , Cinética , Estrutura Molecular , Fenetilaminas/química , Fenilacetatos/químicaRESUMO
The motor corticospinal system can be identified from day E14 in Wistar and HTx fetuses. There are no significant anatomical differences between the two species of rats. In addition, in day E17 Wistar and HTx fetuses cell counts in the cortical mantle (cortical plate, intermediate zone and germinal matrix) are similar. However, in day E20 fetuses there are significant differences in the number of cells in the cortical mantle of the hydrocephalic HTx fetuses compared to that in the Wistar and normal HTx fetuses, their total number of cells being reduced compared to that of the normal HTx and Wistars. Breakdown of the numbers of cells in the different layers shows that in the hydrocephalics there is a significant reduction in the number of cells in the germinal matrix and intermediate zone but, although the number of cells is also reduced in the cortical plate, the reduction is not significant. Measurements of the anterior/posterior width of the pyramid show that its growth is almost complete by day E17 and that on day E20 the measurements are similar in Wistar and normal and hydrocephalic HTx fetuses. These findings suggest that it is only cells generated after day E17 that are missing from the cortex of day E20 hydrocephalic rats. It is known that the motor corticospinal tract axons arise from pyramidal cells in layers 6, 5 and 4 of the cortical plate. These layers are generated earlier than layers 3 and 2 and are almost certainly in place by day E17 and account for why motor corticospinal tract function is spared in younger animals with established hydrocephalus.