Journal of Cell Science 110, 2315-2322 (1997) 2315 Printed in Great Britain © The Company of Biologists Limited 1997 JCS4287 Differential induction of apoptosis in Swiss 3T3 cells by nitric oxide and the nitrosonium cation Shazia Khan1,2, Midori Kayahara1,2, Umesh Joashi2, Nicholas D. Mazarakis2, Catherine Sarraf3, A. David Edwards2, Martin N. Hughes1 and Huseyin Mehmet2,* 1Department of Chemistry, King’s College London, Strand, London WC2R 2LS, UK 2Weston Laboratory, Department of Paediatrics and Neonatal Medicine, and 3Department of Histopathology, Royal Postgraduate Medical School, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK *Author for correspondence (e-mail:
[email protected]) SUMMARY We have investigated the effect of nitric oxide (NO) on decomposition to NO. The apoptotic effect of NO was apoptosis in Swiss 3T3 fibroblasts and compared it to the reduced in the presence of the NO scavenger oxyhaemo- effect of the nitrosonium cation (NO+). Both species globin, or the antioxidants N-acetylcysteine and ascorbic induced apoptosis, confirmed by electron microscopy, acid, whereas in the case of NO+ these antioxidants poten- propidium iodide staining, DNA laddering and activation tiated apoptosis. Glutathione also had a potentiating effect of caspases. The kinetics of triggering apoptosis were on the cytotoxicity of NO+. This suggests that cellular different for the two redox species: NO+ required only a 2 antioxidants may play a role in protecting the cell from NO- hour exposure, whereas NO required 24 hours. Three induced apoptosis while NO+ may trigger apoptosis inde- sources of NO were used: aqueous solutions of NO and two pendently of oxidative stress mechanisms.