Figure 5: Effect of oral sodium bicarbonate administration on cathepsin activity-related fluorescence in mouse xenografts. Tumor bearing mice () were imaged prior to treatment and then received 42 mg of sodium bicarbonate or PBS (p.o.). (a) Subsequent images were taken at 30 minutes, 1, 2, 3, 4, and 5 hours. Fluorescence-based activity is expressed as a percentage of signals taken prior to treatment. The reduction in fluorescence-based activity was statistically significant in sodium bicarbonate-treated mice at all time points (*). No significant change in activation-based fluorescence was observed in PBS-treated mice except at the 1-hour time point (†). (b) Representative image of experiment comparing PBS-treated mouse to bicarbonate-treated mouse.