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PATRICIA MARÍN-GARCÍA Y COLS. AN. R. ACAD. NAC. FARM.

interesting because demonstrate that resorufin fluorescence, in the
presence of BzATP, is not proportional to glutamate concentration
and, therefore, it must not be used as method to measure glutamate
concentration. This recommendation is applicable to the large variety
of assays that also used Amplex Red for quantitating specific
biological compounds (cholesterol, galactose, glucose, …) or enzymes
(monoamine oxidase, PLD, …).

FIGURE 4. Glutamate determination using Amplex® Red Glutamic Acid/
Glutamic Oxidase Assay Kit in absence or presence of BzATP. A working
solution containing 100 µM Amplex® Red reagent, 0.25 U/mL HRP, 0.08 U/mL
L-glutamate oxidase, 0.5 U/mL L-glutamate-pyruvate transaminase, and 200 µM
L-alanine was supplemented with different glutamate concentrations (0.1, 0.5 and

1 mM) alone or with BzATP (10 and 100 mM). After incubation at 37º C,
resorufin fluorescence was measured as indicated in methods section.

In that sense, in a recent report Kukley et al. (10) showed that
catabolism of BzATP, and subsequent adenosine A1 receptor
activation, depressed field potentials (fEPSP) at hippocampal
synapses. This conclusion was reached analysing BzATP hydrolysis

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