Vascular factors in the pathogenesis of uraemic bleeding.

To determine the possible role of vascular factors in the bleeding tendency of uraemic patients, three major factors of the haemostatic system normally present in vascular tissues were studied. Factor VIII-related protein (F VIII) was detected on the vascular intima of 13 patients and 10 normal subjects. Comparable values of plasminogen activator (PA) were found in tissue slices from 7 patients and 7 controls. In contrast, prostacyclin like (PGI2) activity, measured as platelet aggregation inhibitory potency, was significantly higher in specimens from 15 patients with either acute or chronic uraemia than in 10 controls. The latter abnormality, leading to impaired platelet-vessel wall interaction, might contribute to the disturbed haemostasis of uraemic patients.