An improved fluorimetric method for assay of dopa in urine and tissues and its use for determination of urinary dopa, at endogenous level, in different species.

An optimized fluorimetric method is presented which permits the analysis of DOPA in urine or tissues, at endogenous levels. A wide variety of eluates can be analyzed by applying the manual or the automated schedule. The automated manifold, developed for DOPA assay, may be used to estimate norepinephrine (NE) in other samples, by only changing the nature of reagents to be pumped. Amounts of DOPA as low as 0.3 ng/ml of eluate can be detected. Determinations of endogenous DOPA are reported in urinary samples of Humans, Rats, Dogs and Sheeps, and in brain of Rats. The pattern of changes in DOPA urinary excretion has been investigated as a function of time in Rats. Dietary influences have been studied in Man, Rat and Dog. It is concluded that the greatest part of free and conjugated DOPA excreted in urine of these animals has an endogenous origin.