Fluorometric estimation of 4-hydroxy-3-methoxyphenylethyleneglycol sulphate in brain

1. A simple, sensitive, and selective method was developed for the fluorimetric estimation of 4-hydroxy-3-methoxyphenylethyleneglycol sulphate (MOPEG-SO(4)) in rat brain.2. MOPEG-SO(4) was isolated on a DEAE Sephadex column. Fluorescence was measured at 465 nm (excitation at 320 nm) after heating the column eluate with acid and reheating after adding ethylene diamine.3. The concentration in brain of MOPEG-SO(4) increased after blockade of its transport from brain by treatment with probenecid and decreased after inhibiting its synthesis by treatment with alpha-methyltyrosine or pargyline.4. Our studies suggest that measurement in changes in the rate of formation of MOPEG-SO(4) may be a useful index of noradrenaline turnover.