Presence of Metanephrine and Normetanephrine in Normal Human Urine

Abstract

IN 1957, Axelrod reported that epinephrine and norepinephrine were O-methylated at the C-3 position, giving metanephrine (3-O-methylepinephrine) and normetanephrine (3-O-methylnorepinephrine), respectively, in the rat¹ ; in addition, he found that these compounds were normally excreted in rat urine². The excretion of normetanephrine in the urine of humans with pheochromocytoma has also been reported³. More recently, the importance of the pathway for 3-O-methylation of epinephrine has been confirmed in man⁴. This report concerns the identification of metanephrine and normetanephrine of endogenous origin in the urine of normal human males.