Figure 4: Effect of KSO, NPFF, and KP peptides on PGE2 toxicity in rat cortical neurons. Cells were exposed to PGE2 either alone or in the presence of KSO, NPFF, or KP peptides for 24 hours prior determination of cell viability by MTT reduction. The effects of the NPFF receptor antagonist RF9 and the GPR-54 antagonist KP234 were also determined. Results are expressed as % Control MTT reduction (mean ± s.e.m.; ). * versus control; † versus PGE2 alone; one-way ANOVA.