Comparison of the formation of the fluorescent products during the reaction of taurine or GABA with MDA. Expressed as peak area and fluorescence intensity, based on the UV absorption maxima of the fluorescent product, and fluorescence yield corresponding to the formation of the fluorescent products. Taurine or GABA (5.0 mM) was incubated with MDA (5.0 mM) in 0.2 mM PBS (pH 7.4) at 37°C for 24 h. UV absorbance of the fluorescent product of (■) taurine, (●) GABA, (▲) Glu, or (▼) Asp with MDA was measured at 391 nm. Fluorescence yield of the fluorescent product of (□) taurine, (○) GABA, (△) Glu, or (▽) Asp with MDA was measured at Ex 392 nm/Em 456 nm. Data are mean ± S.D. of triplicates.