Phenylalanine and Tyrosine in the Adrenal Medulla

Abstract

Abstract The claim (F ellman 1958, F ellman and D evlin 1958) that large amounts of free phenylalanine are present in the adrenal medulla has been tested using cation exchange and paper chromatographic methods. The concentration of this amino acid was found to be very low (< 20 to 40 μg/g wet wt). Tyrosine — but no m‐tyrosine, phenylserine or 3,4‐dihydroxyphenylalanine (< 20 μg/g) – was detected in small amounts (10 to 20 μg/g). Thus the catecholamine producing cells in the gland do not accumulate free phenylalanine or tyrosine to a level appreciably higher than that in the blood plasma.