Radioenzymatic assay of catecholamines
AssigneeThe Upjohn Company
InventorsGarland A. Johnson, Jacob D. Peuler
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Abstract
A new radioenzymatic assay for catecholamines utilizing the catechol-O-methyl transferase transfer of a methyl group from a labeled methyl donor to the catecholamines followed by isolation of the O-methylated(.sup.3 H)catecholamine and the subsequent measurement of radioactivity.
Claims6
A method for purifying an O-methylated catecholamine selected from the group consisting of O-methylated epinephrine, norepinephrine and dopamine prepared from the catechol-O-methyl transferase catalyzed methylation of the said catecholamine obtained from a mammalian system which comprises preferentially extracting the O-methylated catecholamine from the enzymatic incubation mixture with an organic solvent, repartitioning into an aqueous acid of sufficient strength to protonate the amine function of the O-methylated catecholamine said acid leaving essentially no residue upon evaporation, separating the acid phase from the organic phase, and separating said O-methylated catecholamine from another O-methylated catecholamine or impurity by chromatographic means.
A method for separating O-methylated epinephrine from O-methylated norepinephrine prepared from the catechol-O-methyl transferase catalyzed methylation of the said catecholamine obtained from a mammalian system which comprises preferentially extracting the O-methylated catecholamine from the enzymatic incubation mixture with an organic solvent, repartitioning into an aqueous acid of sufficient strength to protonate the amine function of the o-methylated catecholamine, said acid leaving essentially no residue upon evaporation, separating the acid phase from the organic phase, and chromatographically separating the O-methylated epinephrine from the O-methylated norepinephrine.
Dependencies are inferred from the claim text.