RESUMO
The mechanism behind amyloid formation is unknown in all types of amyloidosis. Several substances can enhance amyloid formation in animal experiments. To induce secondary systemic amyloid (AA-type amyloid) formation, we injected silver nitrate into mice together with either amyloid fibrils obtained from patients with familial polyneuropathy (FAP) type I or polyethylene glycol (PEG). Mice injected with silver nitrate only served as controls. Amyloid deposits were detectable at day 3 in animals injected with amyloid fibrils and in those injected with PEG, whereas in control mice, deposits were not noted before day 12. Our results indicate that amyloid fibrils from FAP patients and even a non-sulfate containing polysaccharide (PEG) have the potential to act as amyloid-enhancing factors.
Assuntos
Amiloidose/metabolismo , Proteína Amiloide A Sérica/biossíntese , Amiloide/isolamento & purificação , Amiloide/farmacocinética , Amiloidose/sangue , Amiloidose/induzido quimicamente , Animais , Doença Hepática Induzida por Substâncias e Drogas , Vermelho Congo , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Histocitoquímica , Humanos , Immunoblotting , Radioisótopos do Iodo , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Hepatopatias/metabolismo , Masculino , Camundongos , Polietilenoglicóis , Polineuropatias/sangue , Pré-Albumina/isolamento & purificação , Pré-Albumina/farmacocinética , Proteína Amiloide A Sérica/análise , Nitrato de Prata , Esplenopatias/induzido quimicamente , Esplenopatias/metabolismo , Distribuição TecidualRESUMO
To detect the variant transthyretin (TTR; Met30) in cerebrospinal fluid (CSF) of familial amyloidotic polyneuropathy (FAP) patients, we have applied a new method using a centrifugal concentrator device and electrospray ionization mass spectrometry (ESI-MS). Only 100 microl of CSF and 30 microl of the antibody for TTR was needed for the analysis. After preparation of the samples with anti-TTR antibody, they were passed through a 1000 kDa cut-off centrifugal concentrator which retained the antibody. By analyzing the obtained filtrate with ESI-MS, three predominant forms of normal and their variant forms of TTR were detected in CSF samples. TTR (Met30), with a molecular weight 32.0 Da higher than the normal form of TTR, was found in all FAP patients' materials. Although the ratio of the three major peaks of TTR were different in each individual, they were always found in CSF and sera. This method will contribute to make a diagnosis of neurologic disorders having a mutant protein in CSF as well as serum.