Hyperdynamic circulation and serotonin levels in patients with liver cirrhosis

Patients with liver cirrhosis and portal hypertension develop hyperdynamic state of circulation. Recent studies indicate that nitric oxide, prostaglandin's, endothelin-1 and serotonin are of major importance in the pathogenesis of portal hypertension and other hemodynamic complications. In our study we estimated the levels of serotonin in sera and 24h urine in 20 patients with liver cirrhosis, using original solid phase extraction procedure. Concentration of serotonin in sera was ranged from 18 to 270 nmol/L and in 24h urine ranged from 97 to 238 nmol/L/24h. In comparison with reference values (determined in range from 280 ?1300 nmol/L in sera and determined in the range from 157.8?1035.4 nmol/ L/24h in urine), a significant fall of serotonin concentration in sera, and urine was noted. A statistically significant correlation between serotonin levels in sera and platelet count was found (p = 0.017). Colour Doppler ultrasonography and peroral fiberpanendoscopy was applied in the whole series to evaluate degree of portal hypertension. The average diameter of portal vein was 16 mm (SD=1.36) and mean blood flow velocity in portal vein was 12 cm/s (SD=1.12). Splenomegaly was approved in the whole group and the mean splenic craniocaudal distance was 17.75 mm (SD=1.65). Esophageal varices grade I?II were detected in 8 (40%) of our patients and reamaining 12 (60%) were grade III?IV. In cirrhotic liver, the spleen congestion, result from platelet degradation. Serotonin, release in to spleen sinusoidal spaces, induces strong vasoconstriction response in portal venous circulation, which contributes to maintain portal hypertension. However, we consider that the decrease of serotonin levels in sera lead to development of hyperdynamic state of circulation.