Assuntos
Doenças das Artérias Carótidas/epidemiologia , Doenças das Artérias Carótidas/metabolismo , Estenose das Carótidas/epidemiologia , Estenose das Carótidas/metabolismo , Peroxidase/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doenças das Artérias Carótidas/patologia , Estenose das Carótidas/patologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores de RiscoRESUMO
OBJECTIVE: To investigate the effect of acepromazine (ACP) on reactive oxygen species (ROS) production by stimulated equine neutrophils. STUDY DESIGN: Ex vivo biochemical experiments. ANIMALS: Isolated neutrophils from healthy untreated horses. METHODS: Neutrophils were incubated with ACP at concentrations of 10(-4), 10(-5) or 10(-6) M and then stimulated with phorbol-myristate-acetate (PMA) before measurement of lucigenin-enhanced chemiluminescence (CL). In a second experiment neutrophils were incubated in the presence of α-keto-γ methylthiobutyric acid (KMB) and treated with ACP at concentrations of 10(-4), 10(-5) or 10(-6) M. Subsequent PMA stimulation lead to neutrophilic ROS production and decomposition of KMB to ethylene, which is measured by gas chromatography. Electron paramagnetic resonance-spin trapping (EPR) analysis was performed with PMA-stimulated neutrophils in the presence of ACP (10(-4), 10(-5) or 10(-6) M) directly added to the cell suspension. In the second experiment, the same concentrations of ACP were pre-incubated with neutrophils, then centrifuged to eliminate the excess of ACP and re-suspended in phosphate buffer before stimulation with PMA. In all experiments, the results of ACP-treated and ACP-untreated stimulated neutrophils were compared. RESULTS: Overall, results obtained with lucigenin-enhanced CL and KMB oxidation were in agreement with those seen in electron paramagnetic resonance spectroscopy. Acepromazine induced a dose-dependent inhibitory effect on neutrophilic ROS production. Electron paramagnetic resonance also showed, at high ACP concentration, the appearance of a cation radical derived from ACP. In contrast, electron paramagnetic resonance study performed with pre-incubated neutrophils showed an important dose-dependent inhibitory effect of ACP. CONCLUSION: The results indicate that ACP can neutralize O.-2 or its by-products during the stimulation of neutrophils. CLINICAL RELEVANCE: These findings may have a therapeutic relevance when phenothiazines are used in horses suffering from inflammatory diseases in which neutrophil activation and ROS production are implicated.
