Platelet and plasma serotonin in patients with liver cirrhosis.

To evaluate the role of serotonin in liver cirrhosis, serotonin was determined by high-performance liquid chromatography in plasma, platelets and ascitic fluids from 14 cirrhotic patients. Plasma-free serotonin was within the normal range, but intraplatelet serotonin was significantly low in cirrhosis (p less than 0.001) and this decrease paralleled the severity of the disease. The concentration of serotonin in ascitic fluids was 12% of the corresponding plasma concentrations. Our data indicate that serotonin levels are influenced by hepatic injury, but the reasons for these changes are still unclear.