Jpn. J. Pharmacol. 72, 381-385 (1996))

Jpn. J. Pharmacol. 72, 381-385 (1996)

Oxidative Stress-Induced Increase in Intracellular Ca2+ and Ca2+-Induced Increase in Oxidative Stress: An Experimental Model Using Dissociated Rat Brain Neurons

Yasuo Oyama (1), Eisuke Okazaki (1), Lumi Chikahisa (1,2), Takayuki Nagano (1) and Chiharu Sadakata (1)

(1) Laboratory of Cellular Signaling, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770, Japan
(2) Cancer Research Laboratory, Taiho Pharmaceutical Co., Ltd., Hanno 357, Japan

Abstract: In order to study the oxidative stress-induced change in intracellular concentration of Ca2+ ([Ca2+]i) and Ca2+-induced oxidative stress, effects of hydrogen peroxide and ionomycin, a calcium ionophore, on rat cerebellar neurons were examined using a flow cytometer and fluorescent dyes: fluo-3 for monitoring [Ca2+]i; 2',7'-dichlorofluorescin, for reactive oxygen species; and 5-chloromethylfluorescein, for cellular nonprotein thiols. Oxidative stress induced by hydrogen peroxide dose-dependently increased [Ca2+]i and decreased the content of nonprotein thiols. Ionomycin increased oxidative metabolism and decreased the content of nonprotein thiols. Results suggest that oxidative stress induces an increase in [Ca2+]i while an increase in [Ca2+]i increases oxidative stress in neurons.

Keywords: Intracellular Ca2+, Oxidative stress, Neuron