title: Elevated brain 5-hydroxytryptophol levels in experimental portal-systemic encephalopathy.
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.
authors.affiliation: Department of Clinical Pharmacology, Lund University Hospital, Sweden.
authors.forename: P B
authors.initials: PB
authors.lastname: Bergqvist
authors.forename: M
authors.initials: M
authors.lastname: Some
authors.forename: G
authors.initials: G
authors.lastname: Apelqvist
authors.forename: A
authors.initials: A
authors.lastname: Helander
authors.forename: F
authors.initials: F
authors.lastname: Bengtsson
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D006897:Hydroxyindoleacetic Acid / Q000032:analysis / Q000378:metabolism; D006917:Hydroxytryptophol / Q000032:analysis / Q000378:metabolism*; D008297:Male; D019965:Neurocognitive Disorders / Q000209:etiology / Q000378:metabolism*; D011167:Portacaval Shunt, Surgical; D051381:Rats; D017207:Rats, Sprague-Dawley; D014364:Tryptophan / Q000494:pharmacology
chemical_list: D006917:Hydroxytryptophol; D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan