HISTAMINE METABOLISM IN HUMAN DISEASE*†

Abstract

Human metabolism of histamine-C14 was investigated in 7 control subjects and in 5 patients with Laennec''s cirrhosis, 3 with bronchial asthma, 3 with histaminic cephalalgia and one with uremia due to chronic glomerulo-nephritis. The radioactivity was rapidly cleared from the blood, and excretion of radioactivity in the urine was usually complete within 30 hr. Separation of the excreted radioactive metabolites by paper chromatog-raphy and radioautography showed imidazoleacetic acid to be the principal product of histamine metabolism. Imidazoleacetic-acid-riboside and 1,4-methylimidazoleacetic acid were also consistently recovered in the urine, but histamine-C14 was not detected. Histamine inactivation and degradation in man is a rapid and complete process, and with these methods, no abnormalities were found in the diseases studied.