5-hydroxyindoleacetic acid (and homovanillic acid) levels in the cerebrospinal fluid after probenecid application in patiens with manic-depressive psychosis

Abstract

Probenecid was administered to 17 depressed, 19 manic and 15 control patients and further to 11 healthy volunteers. Before and after the administration the levels of 5-hydroxyindoleacetic acid (5-HIAA) were determined in cerebrospinal fluid (CSF). In six of the depressed, seven of the manic and seven of the patients from the group of controls and volunteers also homovanillic acid (HVA) was determined in CSF. After the application of probenecid there is a significant increase in 5-HIAA and HVA in the control patients and healthy volunteers but not in the depressed and manic patients. No increase in HVA occurred in the depressed patients but in the manic ones the HVA values were almost as high as in the group of controls and healthy volunteers. It is suggested that the lack of increase in 5-HIAA and HVA after probenecid indicates an inhibition of the synthesis of the acids and thus of the corresponding amines (5-hydroxytryptamine and dopamine) in the brain.