Blood and plasma 5‐hydroxytryptamine levels in patients with cirrhosis

Abstract

Serotoninergic mechanisms are thought to play a role in portal hypertension. Because this biomine is metabolized by the liver, peripheral blood and plasma levels of 5‐hydroxytryptamine and 5‐hydroxyindole acetic acid (the main metabolite of 5‐hydroxytryptamine) were measured in 30 patients with cirrhosis. Whole‐blood 5‐hydroxytryptamine levels were significantly lower in patients with cirrhosis (158 ± 28 nM) than in age‐matched controls (332 ± 19 nM), and no correlation was found between these levels and the severity of cirrhosis. Unconjugated plasma 5‐hydroxytryptamine levels, an indication of the active form of 5‐hydroxytryptamine, were significantly higher in patients with cirrhosis than in controls (6.8 ± 1.7 nM and 3.4 ± 0.5 nM, respectively), and in patients with cirrhosis these levels were higher in Pugh grade A than in Pugh grade C patients. Conjugated‐plasma 5‐hydroxytryptamine levels were not significantly different between patients with cirrhosis (32.2 ± 8.1 nmol/L) and controls (16.4 ± 1.4 nmol/L). Plasma 5‐hydroxyindole acetic acid was significantly lower in patients with cirrhosis than in controls (1.5 ± 0.1 nmol/L and 2.3 ± 0.1 nmol/L, respectively). in conclusion, this study shows that serotoninergic mechanisms are altered in patients with cirrhosis. (Hepatology 1994;20:800–803). Copyright © 1994 American Association for the Study of Liver Diseases