Open AccessElevated Brain 5‐Hydroxytryptophol Levels in Experimental Portal‐Systemic Encephalopathy
Author(s) -
Bergqvist Peter B. F.,
Some Margareta,
Apelqvist Gustav,
Helander Anders,
Bengtsson Finn
Publication year - 1997
Publication title -
pharmacology & toxicology
Language(s) - English
Resource type - Journals
eISSN - 1600-0773
pISSN - 0901-9928
DOI - 10.1111/j.1600-0773.1997.tb00394.x
Subject(s) - encephalopathy , medicine
Abstract: Brain tissue levels of the two serotonin metabolites 5‐hydroxytryptophol and 5‐hydroxyindole‐3‐acetic acid (5‐HIAA) were measured in porta‐caval shunted rats, an in vivo model of portal‐systemic encephalopathy. An intraperitoneal challenge of L‐tryptophan (280 mg/kg body weight) to sham‐operated rats was also instituted to increase the brain serotonin metabolism in these rats. The results revealed significant increases in 5‐hydroxytryptophol (by 31%) and 5‐HIAA (by 87%) brain levels in porta‐caval shunted rats as compared to sham‐operated controls. The brain 5‐hydroxytryptophol‐to‐5‐HIAA ratio was lower in the porta‐caval shunted rats. The 5‐hydroxytryptophol levels in sham rats after the L‐tryptophan challenge were intermediate between the porta‐caval shunted and sham rats but not statistically significant for either group. These results suggest that increased brain 5‐hydroxytryptophol levels might be associated with the pathogenesis of portal‐systemic encephalopathy. Further, the elevated brain 5‐hydroxytryptophol levels in experimental portal‐systemic encephalopathy are probably a result of the increased brain serotonin metabolism prevailing in this condition rather than changes in the brain redox potential.