Prostacyclin can Replace Heparin for Haemodialysis in Dogs

Prostacyclin, produced by vascular endothelium, is the most potent inhibitor of platelet aggregation known to man. To assess its effects on platelets during dialysis ten greyhounds were dialysed for 90 minutes with cuprophan coils. At the end of dialysis arterial platelet counts (% of initial value) were significantly higher in the five dogs in which prostacyclin had been infused (115.7 ± 8.6) than in the animals in which heparin alone had been used (77.8 ± 16.8, < 0.05). Prostacyclin reduced the extraction of platelets by the dialyser. The screen filtration pressure, a measurement of platelet aggregates in blood leaving the dialyser, remained unelevated in the prostacyclin treated animals (80 ± 11.3 mm Hg) but rose significantly in those infused with heparin alone (249 ± 57 mm Hg, < 0.02). In another five dogs infused with prostacyclin but no heparin, dialysis did not reduce platelet count, elevate the screen filtration pressure or alter the overall clotting tests.

Thus prostacyclin enables haemodialysis to be carried out without the undesired effects on platelets and haemostasis that are associated with the use of heparin.