Issue Archive

Hydrogen peroxide preconditioning protects PC12 cells against apoptosis induced by oxidative stress

Tang Xiaoqing, Chen Jing, Tang Erhu, Feng Jianqiang, Chen Peixi

Department of Physiology,Zhongshan Medical College,Sun Yat-sen University.Guangzhou 510080,Guangdong

Abstract

Oxidative stress can induce significant cell death by apoptosis. We explore whether prior exposure to H_(2)O_(2)(H_(2)O_(2) preconditioning) protects PC12 cells against the apoptotic consequences of subsequent oxidative damages and what role the ATP sensitive potassium (K_(ATP)) channels play in the preconditioning protection. PC12 cells were preconditioned with 90 min exposure to H_(2)O_(2) at 10 #mu#mol/L, followed by 24-h recovery and subsequent exposures to different concentrations (20, 30, 50 and 100 #mu#mol/L) of H_(2)O_(2) for 24 h respectively. We used PI staining flow cytometry (FCM) to observe the apoptosis of PC12 cells. It was shown that 24-h exposures to H_(2)O_(2) at 20, 30, 50 and 100 #mu#mol/L respectively induced substantial cell apoptosis, which was greatly prevented in the preconditioning cells, indicating that H_(2)O_(2) preconditioning protected PC 12 cells against apoptosis induced by H_(2)O_(2). Administration of pinacidil (10 #mu#mol/L), an K_(ATP) channel activator, significantly attenuated the apoptosis of PC12 cells induced by H_(2)O_(2) at 30 and 50#mu#mol/L for 24 h respectively. Glybenclamide (10 #mu#mol/L), a K_(ATP) channel inhibitor, significantly suppressed or abolished the protective effects caused by the pinacidil but not by H_(2)O_(2) preconditioning. However, when both H_(2)O_(2) preconditioning and pinacidil were coapplied, their protection against the apoptosis of PC12 cells was much stronger than that of the individual one of them. These results suggest that H_(2)O_(2) preconditioning protects PC12 cells against apoptosis and that the activation of K_(ATP) channels is not involved in, but synergetically enhances adaptive protection of H_(2)O_(2) preconditioning.

Key words: preconditioning;Hydrogen peroxide;PC12 cells;;

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

Tang Xiaoqing, Chen Jing, Tang Erhu, Feng Jianqiang, Chen Peixi. Hydrogen peroxide preconditioning protects PC12 cells against apoptosis induced by oxidative stress. Acta Physiol Sin 2005; 57 (2): (in Chinese with English abstract).