Lipopolysaccharide decreases oxygen consumption by Mono Mac 6 cells; an electron paramagnetic resonance oximetry study

摘要

The rule of oxygen consumption in the luuuan acute monoL-ytic leukemia-derived cell line, Mono Mac 6, in response to lipopolysaceluiiide (I,PS) in vitro was measured by electron paramagnetic resonance speeiroscopy using an oxygen-sensitive spin-label, 4-oxo"2,2,6,6-tetramethylpiperidine-d16-1-oxyl (15N-PDT). Lipopolysaccharide impaired oxygen consumption in a dose-tlependent manner which was shown to he mediated by mitochondrial dysfunction and could be augmented by pretrealment of the cells with interleroii-y. Treatment of the cells with anti-CD 14 monoclonal antibody failed to inhibit the I.PS-induced effects on cellular respiration. These results suggest that LPS can directly reduce normal cellular oxygen consumption possibly via a CD14-indepeiKlent pathway. This alteration of mitochondria! function by LI'S may be responsible for the observed cell damage during sepsis.