Figure 1: Time course of rat brain glutamate decarboxylase activity by manometric and fluorimetric methods. One ml aliquots of purified rat brain GAD with protein concentration of 0.12 mg were incubated in the presence of 100 μl glutamate solution (10 mM) at 37°C and the rate of glutamate decarboxylation or changes of fluorescence intensities were measured by manometric (-•- ) and fluorimetric (-▪- ) methods respectively for a period of up to 60 mim. Each point represents mean ± SD of 6 determinations.