Elghozi J L, Laude D
Laboratoire de Pharmacologie, INSERM U7, Faculté de Médecine Necker-Enfants Malades, Paris.
C R Seances Soc Biol Fil. 1989;183(1):8-25.
5-Hydroxyindoleacetic acid (5-HIAA) is the chief end-product of serotonin metabolism. The gastrointestinal tract is the main source of urinary 5-HIAA. The rest originates from the degradation of brain or platelet serotonin stores. Main abnormalities in 5-HIAA excretion have been observed in carcinoid tumors (elevation) or hyperphenylalaninemia (diminution) as well as in migraine. Estimation of renal blood flow is a new application of 5-HIAA measurements. This stems from the elimination process of this weak organic acid which combines glomerular filtration and proximal tubular secretion. Thus 5-HIAA is extracted by the kidney in high amounts as indicated by a high renal extraction ratio. The renal clearance of 5-HIAA seems a good estimation of renal blood flow. Therefore fluctuations of this endogenous compound could be used to quantify the effects of physiological manipulations or drugs on renal blood flow.
