ATP depletion and loss of cell integrity in anoxic hepatocytes and silica-treated P388D1 macrophages

Abstract

The relationship between ATP depletion and the loss of cell integrity was examined in the killing of hepatocytes by anoxia and P388D1 macrophages by silica. ATP depletion is a feature of the reaction to either hazard. Treatment of hepatocytes, however, with antimycin, oligomycin, sodium azide, or N,N'-dicyclohexylcarbodiimide produced a rate and extent of ATP depletion comparable with anoxia without significant loss of viability. Treatment of P388D1 cells with 2-deoxyglucose plus antimycin, oligomycin, or sodium azide reproduced the loss of ATP accompanying silica particle intoxication. Again, there was no loss of viability. These data dissociate the loss of cellular ATP from the genesis of lethal injury in both cell types. ATP depletion was, however, associated with a loss of lysosomal integrity. With the metabolic inhibitors, loss of lysosomal integrity occurred in the absence of irreversible cell injury over the time course that anoxia and silica intoxication significantly damaged the cells. This implies that neither hazard produces lethal damage through mechanisms dependent on intracellular lysosomal enzyme release. While ATP depletion can cause lysosomal rupture in P388D1 macrophages, phagocytosis of silica particles in the absence of extracellular Ca2+ ions is associated with release of lysosomal contents without depletion of ATP or loss of cell integrity. Silica particles are concluded to interact directly with both the plasma and lysosomal membranes. The former leads to Ca2+ influx with resultant cell death and ATP depletion. The latter leads to release of lysosomal contents that is not followed by irreversible cell injury.

Mechanisms of Neutrophil-Dependent and Neutrophil-Independent Endothelial Cell Injury

“…Miti gating this, however, is the fact that oxidantstressed cells are not 'resting'. Past studies have shown that an early response of cells to a number of injurious agents including H2O2 is a rapid depletion of intracellular ATP stores [13,14], Studies in our laboratory confirmed this in H202-treated RPAEC [15]. Within 10 min of exposure to H2O2, greater than 75% of the cellular ATP was lost.…”

Cytochrome c Release upon Fas Receptor Activation Depends on Translocation of Full-length Bid and the Induction of the Mitochondrial Permeability Transition

“…Measurement of ATP Content-The cellular ATP content was determined by modification of the firefly luciferin-luciferase method as described previously (16). Briefly, cells in RPMI medium from 24-well plates were transferred into 1.5-ml microcentrifuge tubes, and 20 l of trichloroacetic acid was added to give a final concentration of 3%.…”

Hepatocellular carcinoma cells resist necrosis during anoxia by preventing phospholipase-mediated calpain activation

“…ATP was quantitated using the luciferin/luciferase assay (Kane et al, 1985). Bioluminescence was quantitated in a luminescence spectrometer (model LS-50; Perkin-Elmer Corp., Norwalk, CT).…”