Homovanillic acid, vanillylmandelic acid and 5-hydroxyindole-3-acetic acid are undetectable in urine of the muskrat.

The muskrat (Suncus murinus) may be useful as a new experimental animal. In order to evaluate some biochemical characteristics of this animal, urinary excretion of homovanillic acid, vanillylmandelic acid and 5-hydroxyindole-3-acetic acid in the muskrat was determined by high-performance liquid chromatography (HPLC) with electrochemical detection. These acid metabolites of catecholamines and serotonin were not detectable or barely detectable (vanillylmandelic acid) in the urine of the muskrat in comparison with human, dog, rat or mouse. The secretion and/or metabolism of these neurotransmitter amines in the muskrat seem to be considerably different from those in other mammals.