Plasma from Patients with Hepatic or Renal Failure Stimulates Prostacyclin Release from “Exhausted” Rat Aorta Slices

Slices of rat aorta (1.5 to 2 mg wet weight) were washed several times in tris buffer until no further release of anti-aggregating activity could be detected. These “exhausted” aorta fragments were then incubated for 60 to 120 min. at room temperature with 250 μl platelet-poor plasma from either a healthy subject or from a patient with hepatic or renal failure. 100 ul of supernatant plasma were subsequently added to 300 ul normal human platelet-rich plasma; the mixture was challenged one minute later with ADP (2 to 4 μM final concentration) and platelet aggregation recorded.

The plasmas from 6/6 uraemic patients undergoing maintenance haemodialysis stimulated prostacyclin release more than the simultaneously studied normal plasmas.

The 17 patients with liver disease were classified using Child’s criteria for hepatic functional reserve. Stimulation of prostacyclin release was found with the plasma of 4/4 patients with advanced hepatic dysfunction, 4/6 patients with moderately impaired hepatic function and 4/7 patients with good hepatic function.

Enhanced prostacyclin release may play a role in the pathogenesis of the haemorrhage diathesis of patients with renal or hepatic failure.