Simultaneous Determination of 5-Hydroxytryptamine and Catecholamines in Tissues Using a Weak Cation Exchange Resin

摘要

During the past decade, a number of procedures have been used for routine assay of catecholamines and the indoleamine, serotonin, in various tissues. Many of these procedures do not allow simultaneous assay of the amines, or, if they do, as in the case of some solvent extraction procedures, do not allow for separation of amines from their precursor amino acids. The successful application of the weak cation exchange resins by some authors for one or two amines made it possible for us to adapt and improve those methods and, at the same time, to study various parameters of the procedure which have not been previously reported in order to increase the versatility of the assay method. The procedure can be used for simultaneous determination of norepinephrine, epinephrine, dopamine and serotonin. Basically, the methods involve the deproteinization of the tissue with either perchloric acid or ethanol, adsorption of the amines on the weak cation exchange resin Bio-Rex 70, elution and spectrofluorometric determination of the amines. The advantages of the method described in this paper over other published ones are: (a) the purification steps of the amines are greatly reduced, requiring only two-and-one-half hours to run up to 50 samples through the columns, (b) the recovery of the amines is higher, (c) one can determine quantitatively 20 ng of each of the four amines in one tissue sample, and (d) the method is highly reproducible.