Fig. (4) Cytokine-induced apoptosis of fetal lung epithelial cells is NO dependent. (A) The cells were pre-incubated with or without 1400W (25 􀀁M) and then incubated with cytokines for 24 h. Total nitrogen oxides were measured in the media. (B) The cells were preincubated with or without 1400W (25 µM) for 1 h and followed by incubation with cytokines for 24 h. Cell death was determined by dual fluorescence photomicroscopy utilizing Rhodamine 123 and YoPro-1. The data shown were representative of three experiments (*p<0.05).