[Serotonin and monoamineoxidase activity in platelets of children]

We examined 5-HT concentration and monoamine oxidase activity in the platelets. We observed 55 children, 30 healthy and 25 with neuropathological situations. No significant difference exists between two groups. MAO activity is not dependent from 5-HT concentration. As the enzyme seems to exist in multiple forms, the type B would be present in the platelets. This form presents less affinity for serotonin. If MAO do not act on platelets 5-HT levels, another mechanism might be to regulate 5-HT concentration in the platelets.