THE PROSTACYCLIN STIMULATING PLASMA FACTOR ACTIVITY IMPROVES THROMBORESISTANCE ONLY IF VASCULAR PGI(2)-PRODUCTION IS INTACT

PGI(2) is important in regulating platelet vessel wall interaction (1) . In perfusion chamber experiments the amount of PGI(2) formed was inv ersely related to the amount bf platelets deposited (2). In 1978 a pla sma factor was described which stimulates vascular PGI(2)-production ( 3). In later years, this activity has been monitored in different pati ent groups (for review see 4). Interestingly, it has been found that d iseases associated with an increased bleeding tendency such as uraemia (5) or hepatic failure (6) were associated with an increased PF-activ ity while others with an enhanced thrombophilia sometimes show an abse nce of PF-activity (7). Recently, the PGI(2) stimulating plasma factor has been purified and cloned (8). It was the aim of these experiments to assess whether PF-activity plays a role in local hemostasis regula tion under in-vivo flow conditions and whether this is dependent on th e presence of an intact PGI(2)-formation. Copyright (C) 1996 Elsevier Science Ltd