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

Abstract
1 A simple, sensitive, and selective method was developed for the fluorimetric estimation of 4-hydroxy-3-methoxyphenylethyleneglycol sulphate (MOPEG-SO4) in rat brain. 2 MOPEG-SO4 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-SO4 increased after blockade of its transport from brain by treatment with probenecid and decreased after inhibiting its synthesis by treatment with α-methyltyrosine or pargyline. 4 Our studies suggest that measurement in changes in the rate of formation of MOPEG-SO4 may be a useful index of noradrenaline turnover.