Variations in blood platelet-activating-factor levels after protamine reversal of heparin in humans.
The potent inflammatory mediator PAF-acether (PAF = platelet-activating factor) can produce the same hemodynamic and hematological effects as protamine infusion. In 10 patients, blood PAF and precursor levels were measured in the left atrium, the pulmonary and the radial artery before and after protamine reversal of heparin during coronary artery bypass graft. Blood PAF level in the left atrium increased 6-fold (17 +/- 12 pg.ml-1 vs 98 +/- 46 pg.ml-1, P = 0.03) after protamine infusion. By contrast, a 4-fold decrease was observed in the pulmonary artery blood (130 +/- 48 pg.ml-1 vs 31 +/- 23 pg.ml-1, P = 0.03) and a 9-fold decrease was noted in the radial artery blood (285 +/- 104 pg.ml-1 vs 31 +/- 15 pg.ml-1, P = 0.01). No cardiovascular impairment was observed but all patients exhibited thrombocytopenia. After protamine, PAF in the left atrium reached lower levels than those observed in the pulmonary and radial artery before protamine infusion. Moreover, no significant correlation was observed between platelet counts and PAF levels. Thus PAF seems not to mediate the platelet drop induced by heparin-protamine complexes. A positive correlation was obtained between leukocyte counts in the pulmonary artery and PAF levels in the left atrium (r = 0.78, P = 0.02). Protamine infusion may stimulate PAF biosynthesis by leukocytes in the lung, on the one hand, and accelerate the disappearance of PAF in the arterial bed, on the other hand.
Nathan
N
N
Department of Anaesthesiology, CHU Dupuytren, Limoges, France.
Denizot
Y
Y
Feiss
P
P
Cornu
E
E
Benveniste
J
J
Arnoux
B
B
D001026:Coronary Artery Bypass; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006494:Heparin Antagonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010972:Platelet Activating Factor / Q000031:analogs & derivatives / Q000032:analysis*; D011479:Protamines / Q000494:pharmacology*
D006494:Heparin Antagonists; C029271:O-deacetyl platelet activating factor; D010972:Platelet Activating Factor; D011479:Protamines