AJP - Cell Physiology, Vol 270, Issue 1 C115-C124, Copyright © 1996 by American Physiological Society
Alterations in reactive oxygen, pH, and calcium in astrocytoma cells during lethal injury
Y. Wu, B. M. Taylor and F. F. Sun
Department of Cell Biology and Inflammation Research, Upjohn Laboratories, Kalamazoo, Michigan 49001, USA.
Exposure of cultured human astrocytoma cells to iodoacetic acid results in
rapid depletion of cellular ATP and cell death. Pathophysiological changes
in the injured cells, including formation of reactive oxygen species (ROS),
cell viability, glutathione, pH, and cytosolic calcium, were characterized
at the cellular level via fluorescence microscopy. After iodoacetic acid
treatment, cellular ATP and intracellular glutathione fell sharply to
undetectable levels within 2 h. ROS, as detected by the oxidation of
dichlorofluorescein, appeared in 20 min and reached a maximum before the
loss of membrane integrity. Cells became acidotic within 10 min. Cytosolic
free calcium concentration exhibited a slow increase and then a sharp
influx shortly before the rupture of the cell membrane. The addition of
lipophilic antioxidants, nordihydroguaiaretic acid or the troloxamine
U-78517F, eliminated the accumulation of ROS and delayed the onset of cell
death without affecting other parameters observed in the early phase of the
injury. We conclude that ROS is formed and may play important roles during
lethal cell injury caused by energy depletion.
