Abstract
A series of studies of monoamines and their metabolism in a variety of human tissues indicate that there are aging effects that may alter neurotransmitter substances. Monoamine oxidase (MAO) activity has a significant positive correlation with age in plasma and blood platelets of normal subjects and patients suffering from depressive disorders. Monoamine oxidase and age correlate positively in hindbrain and in eight separate areas of human brains from patients who died from a variety of causes. Hindbrain norepinephrine concentration progressively decreases with advancing age (r = −0.44, P < 0.01) while no changes were noted for serotonin (5-HT) and 5-hydroxy.indoleacetic acid (5-HIAA). Hindbrain norepinephrine concentration has a significant negative correlation with MAO (r = −0.41, P < 0.025) and hindbrain 5-HIAA has a significant positive correlation with MAO (r = +0.66, P = Federation Proc. 34: 103–107, 1975. Keywords Monoamine Oxidase Blood Platelet Amine Oxidase Monoamine Oxidase Activity Monoamine Metabolite These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.