Anticoagulantly active heparin-like molecules from mast cell-deficient mice.
To assess the contribution of mast cells to the maintenance of blood fluidity, the hindlimb vasculature of mast cell-deficient mice (W/Wv) and littermates containing normal levels of mast cells (+/+), were perfused with purified human thrombin and antithrombin. Enzyme-inhibitor complex generation within the vasculature was enhanced to a comparable extent for W/Wv and +/+ mice over the uncatalyzed rate, that level of complex produced within a similar time interval in the absence of heparin. Perfusion of purified Flavobacterium heparinase prior to infusion of the hemostatic components, or perfusion of antithrombin modified at the heparin-binding domain, reduced W/Wv and +/+ hindlimb thrombin-antithrombin complex formation to the uncatalyzed rate. To further define the cellular source of the vascular-associated heparin-like molecules, endothelial cells isolated from epididymal fat pads of W/Wv and +/+ mice were grown in vitro. The acceleration of thrombin-antithrombin interactions in the presence of endothelial cell-derived glycosaminoglycans was similar for W/Wv and +/+ mice, was abolished with purified bacterial heparinase, and was expressed to only a minor extent when utilizing modified antithrombin. The biologically active mucopolysaccharides appear to be present on the cell surface.
J A
JA
Marcum
J B
JB
McKenney
S J
SJ
Galli
R W
RW
Jackman
R D
RD
Rosenberg
D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism; D000818:Animals; D000925:Anticoagulants / Q000096:biosynthesis*; D001808:Blood Vessels / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology / Q000378:metabolism; D004822:Epididymis / Q000166:cytology / Q000378:metabolism; D006493:Heparin / Q000096:biosynthesis*; D006614:Hindlimb / Q000098:blood supply; D008297:Male; D008407:Mast Cells / Q000166:cytology / Q000502:physiology*; D051379:Mice; D008817:Mice, Mutant Strains / Q000033:anatomy & histology / Q000235:genetics* / Q000378:metabolism; D010477:Perfusion
D000925:Anticoagulants; D006493:Heparin