Enhanced lipid peroxidation by extracellular ATP in PC12 cells.

Recently we have demonstrated that extracellular ATP acts as an excitatory neurotransmitter and enhances cell death in the presence of ferrous ions. By using a newly developed cis-parinaric acid fluorescence technique, we demonstrated that ATP, in a dose dependent manner, enhanced the increased membrane lipid peroxidation in PC12 cells when cells were incubated with micromolar FeCl2/DTP. P2 purinoceptor agonists, alpha,beta-methylene ATP and 2-methylthio-ATP, induced PC12 cell lipid peroxidation, but to a lesser extent than ATP. ATP-induced Ca(2+) influx via P2 purinoceptor activation significantly increased the intracellular Ca(2+)concentration, which may have triggered a free radical generating cascade(s), and led to membrane lipid peroxidation and cell death. Since oxidative stress has been implicated in certain neurodegenerative diseases such as aging, extracellular ATP may contribute to neuronal cell death by an oxidative mechanism involving lipid peroxidation.