Degradation of prostacyclin in the plasma of patients with terminal liver insufficiency.

It has been suggested earlier that the increased bleeding tendency observed in patients with hepatic coma is due to prostaglandin I2. Various experimental studies have reported an increased prostaglandin I2-formation, an enhanced plasma factor activity and a prolonged synthesis in-vitro. However, the rate of degradation of prostaglandin I2 in plasma could be another determinant alterating the locally available biologically active substance but this has not been examined so far. Thus, we examined the half-life of synthetic prostaglandin I in-vitro in plasma from 25 patients with terminal liver insufficiency in different stages of hepatic coma. In 8 healthy volunteers a 6 months follow up showed no significant change. The half-life of prostaglandin I in controls was 10.21 +/- 2.70 minutes, no different from coma stage I (10.16 +/- 1.36 minutes), coma stage II (10.86 +/- 2.24 minutes), coma stage III (10.95 +/- 3.06 minutes) or coma stage IV (12.07 +/- 2.88 minutes). However, a modest trend towards a prolongation and an increase in standard deviation with the coma stage can be noted. No influence of various drugs commonly used in these patients could be seen. It can thus be concluded that there is no important difference in degradation speed of prostaglandin I2 in the plasma of patients with terminal liver insufficiency, which could account for the increased bleeding tendency.