Preparations of synthetic phospholipids promote procoagulant activity on damaged vessels: studies under flow conditions.
BACKGROUND
The possibility of developing synthetic platelet substitutes that could promote hemostasis with prolonged shelf-life and increased safety is an appealing one.


METHODS
Preparations containing synthetic phospholipids were incorporated into blood samples (1.15 mg/mL) in which platelets and white cell counts had been experimentally reduced by a filtration procedure. Vesicles containing phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), or combinations of PC and PE and of PC and PS were tested in this system. Blood was recirculated (10 min; shear rate, 250/sec) through a perfusion chamber containing vascular segments. The ability of the various phospholipid preparations to promote fibrin formation on the damaged subendothelium was evaluated morphometrically and expressed as the percentage of fibrin coverage. Generation of thrombin in the system was monitored through the measurement of prothrombin fragments 1 and 2.


RESULTS
Vesicles containing PC, PI, PE:PC (1:1), or PS:PC (1:3) increased fibrin deposition on the subendothelium (64.5 +/- 9.8%, 32.7 +/- 6.3%, 58.3 +/- 6.5%, and 46.6 +/- 15.2%, respectively; p < 0.01 vs. 11.5 +/- 1.2% in thrombocytopenic blood). Vesicles containing PE, PS, or PS:PC (3:1) did not show procoagulant effect.


CONCLUSIONS
Synthetic phospholipid preparations promote a local procoagulant activity at sites of vascular damage when they are incorporated into thrombocytopenic blood maintained under flow conditions.
Galán
A M
AM
Hemotherapy and Hemostasis Service, Hospital Clinic, Faculty of Medicine, Barcelona, Spain.
Hernández
M R
MR
Bozzo
J
J
Reverter
J C
JC
Estelrich
J
J
Roy
T
T
Mazzara
R
R
Ordinas
A
A
Escolar
G
G
D000818:Animals; D001012:Aorta, Abdominal / Q000187:drug effects / Q000473:pathology*; D001777:Blood Coagulation / Q000187:drug effects*; D001783:Blood Flow Velocity; D001802:Blood Substitutes / Q000494:pharmacology; D005337:Fibrin / Q000032:analysis; D006801:Humans; D066298:In Vitro Techniques; D010316:Particle Size; D010446:Peptide Fragments / Q000032:analysis; D010743:Phospholipids / Q000097:blood / Q000494:pharmacology*; D011516:Prothrombin / Q000032:analysis; D011817:Rabbits
D001802:Blood Substitutes; D010446:Peptide Fragments; D010743:Phospholipids; C045879:prothrombin fragment 1.2; D011516:Prothrombin; D005337:Fibrin