There is increase in the daily urinary excretion of dopamine (DA), norepinephrine (NE), epinephrine (E), and 3-methoxy-4-hydroxymandelic acid (VMA) with age. The mean output in micrograms per 24 hours for various age groups is as follows: birth to 1 year-DA 60.9 (± 24.3), NE 10.6 (± 3.4), E 1.3 (± 1.2), VMA 569 (± 309); 1 through 5 years—DA 124.1 (± 40.7), NE (18.8 ± 7.0), E 3.2 (± 2.7), VMA 1348 (± 433); 6 through 15 years—DA 169.3 (± 72.6), NE 37.4 (± 16.6), E 4.8 (± 2.4), VMA 2373 (± 698); over 15 years—DA 249.1 (± 74.9), NE 50.7 (± 15.7), E 7.1 (± 3.3), VMA 3192 (± 699).
The studies suggest that the daily output of these compounds in the various age groups is similar when related to body surface area after infancy.
