Intravascular cysteinyl-leukotriene formation by clotting whole human blood. Evidence from clamped umbilical vein segments and thrombus specimens.
We have recently demonstrated that contact activation of the intrinsic coagulation cascade in vitro is accompanied not only by thromboxane (TX) B2 generation but also by the formation of 5-lipoxygenase-derived cysteinyl-leukotrienes (LT). In our present study we have investigated the effects of the vascular wall on the eicosanoid formation by whole human blood. Incubation of whole human blood in clamped segments of autologous umbilical veins incubated in oxygenated Tyrode solution led to a time-dependent generation of cysteinyl-LT and TXB2 in the blood samples. A clear dissociation in the time-dependent production profiles was observed with cysteinyl-LT practically reaching a plateau phase at 60 min while TXB2 levels increased up to 90 min. In blood samples incubated in glass tubes for 60 min TXB2 production was about 13 times higher and cysteinyl-LT formation only about half as much as in the umbilical vein segments indicating a differential stimulation of both the cyclooxygenase and 5-lipoxygenase pathway of arachidonic acid metabolism in these experiments. By reverse phase HPLC the immunoreactive cysteinyl-LT were identified as a mixture of LTC4, LTD4 and LTE4. Since the data were suggestive of intravascular cysteinyl-LT formation in thrombotic vessels, thrombus specimens from patients with acute deep vein thrombosis of the lower limb were analysed for these compounds by combined reverse phase HPLC and specific radioimmunoassay.(ABSTRACT TRUNCATED AT 250 WORDS)
Weide
I
I
Department of Pharmacology and Toxicology, Ruhr University, Bochum, Germany.
Winking
M
M
Simmet
T
T
D000328:Adult; D001094:Arachidonate 5-Lipoxygenase / Q000097:blood; D001777:Blood Coagulation; D003250:Constriction; D006801:Humans; D007231:Infant, Newborn; D017997:Leukotriene C4 / Q000096:biosynthesis* / Q000097:blood; D017998:Leukotriene D4 / Q000096:biosynthesis* / Q000097:blood; D017999:Leukotriene E4 / Q000096:biosynthesis* / Q000097:blood; D013924:Thrombophlebitis / Q000097:blood*; D013927:Thrombosis; D013929:Thromboxane B2 / Q000096:biosynthesis / Q000097:blood; D014471:Umbilical Veins
D017997:Leukotriene C4; D013929:Thromboxane B2; D017998:Leukotriene D4; D017999:Leukotriene E4; D001094:Arachidonate 5-Lipoxygenase