RESUMO
Previous studies have suggested a defect in phosphorus metabolism in Alzheimer's disease (AD) gray matter. We have studied phosphorus metabolites in both gray and white matter in autopsy specimens of nine subjects with late-stage AD, three with Pick's disease and seven age-matched controls. Phosphorus metabolites sugar phosphate (SU), phosphomonoester (PME), phosphodiester (PD), and inorganic phosphate (PI) were quantified as mole percentages in regional neocortical specimens using nuclear magnetic resonance spectroscopy. Senile plaque (SP) and neurofibrillary tangle (NFT) counts were determined in adjacent cortical sections. In the inferior parietal lobule gray and white matter, mole percentage normalized PME, and PD were significantly greater than control values in both AD and Pick's disease. A significant correlation was found between PD and NFT in AD parietal gray matter. Our data indicates that phosphorus metabolite alterations are present in two cortical degenerative diseases and are not likely to be specific for AD.
Assuntos
Doença de Alzheimer/metabolismo , Demência/metabolismo , Fósforo/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Encéfalo/patologia , Química Encefálica/fisiologia , Córtex Cerebral/patologia , Demência/patologia , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Emaranhados Neurofibrilares/fisiologia , Compostos Organofosforados/metabolismo , Fosfatos/metabolismo , Isótopos de FósforoRESUMO
Biotransformation of both R-(+)-nicotine and R-(+)-N-methyl-nicotinium acetate in male Hartley guinea pigs affords a new quaternary amine metabolite, which was isolated and purified from urine by preparative HPLC. The structural analysis of the metabolite was carried out using UV spectrophotometry, direct thermospray mass spectrometry, and Fourier transform 1H-NMR spectroscopy. The structure of the metabolite was confirmed by synthesis and shown to be a mixture of the cis-1'S,2'R-, and trans-1'R,2'R-diastereomers of N-methyl-N'-oxonicotinium ion, formed in the ratio 1.6:1.0, respectively. S-(-)-Nicotine under similar conditions does not undergo this biotransformation.
Assuntos
Nicotina/análogos & derivados , Nicotina/metabolismo , Compostos de Piridínio , Animais , Biotransformação , Cromatografia Líquida de Alta Pressão , Cobaias , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas , Nicotina/síntese química , Nicotina/isolamento & purificação , Nicotina/urina , Espectrofotometria Ultravioleta , EstereoisomerismoRESUMO
Fluorine-19 nuclear magnetic resonance spectroscopy is used to detect the in vitro uptake of tetrafluoroputrescine, a novel putrescine analogue, in red blood cells.
Assuntos
Eritrócitos/análise , Flúor , Putrescina/análogos & derivados , Animais , Espectroscopia de Ressonância Magnética , Putrescina/sangue , RatosRESUMO
Carbon-13 NMR is utilized to demonstrate the attack of bisulfite anion on uridine, 5-fluorouridine, and uridine 5'-monophosphate. The attack produces a pair of diastereomeric adducts similar in structure to those seen in the uracil series. Intensity data from the equilibrium system give an estimate for the individual equilibrium constants. Thymidine and thymidine 5'-monophosphate show no evidence of nucleophilic attack by bisulfite. This evidence indicates that bisulfite addition to nucleosides and nucleotides models the enzymatic methylation of uridine by the enzyme thymidylate synthetase better than the uracil bisulfite system.