Age dependent normal values of histamine and histamine metabolites in human urine.

We collected morning urine samples from normal healthy persons, who had not yet breakfasted, in the age range of 2-61 years and measured urinary excretion of histamine and its metabolites N tau-methyl-histamine and N tau-methylimidazoleacetic acid. The values obtained (expressed in terms of urinary creatinine excretion), were age dependent up to the age of 12. Thereafter, values stabilized and were no longer age dependent.