RESUMO
Incubation of murine peritoneal macrophages with 7beta-hydroxycholesterol (7beta-OH) for 24 hr led to dose-dependent reduction in cellular glutathione content as well as nitrite levels in the medium. Treatment with an inorganic form of selenium, sodium selenite which is a potent antioxidant, elevated the cellular glutathione levels and decreased nitrite levels. Our results suggest that 7beta-OH may exert its pro-atherogenic effect by inhibiting glutathione synthesis and nitric oxide production by macrophages present in the arterial wall and thus, impair the cellular antioxidant defense system.
Assuntos
Animais , Artérias/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Hidroxicolesteróis/farmacologia , Macrófagos/metabolismo , Macrófagos Peritoneais/metabolismo , Camundongos , Óxido Nítrico/biossíntese , Selênio/metabolismo , Fatores de TempoRESUMO
A simple method for treating bovine blood samples for direct detection of T. annulata in carriers, after polymerase chain reaction (PCR) amplification of small subunit ribosomal RNA (SSU rRNA) gene is described. The threshold of detection of the PCR-assay was an erythrocytic parasitaemia of 0.00008% corresponding to 16 infected bovine erythrocytes. In 50 known carriers, 42 were positive in PCR, in which 8 cattle revealed presence of T. annulata in stained blood smear under microscope.