ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Experiments were carried out to characterize plasma fibronectin deposition onto material surfaces exposed to plasma solutions. Under nonclotting conditions, the amount of fibronectin adsorption on the surfaces, determined by an indirect radioactive antibody assay, was maximal at low plasma concentrations (0.1%). At higher concentrations of plasma, other plasma proteins appeared to compete with and inhibit adsorption of fibronectin. Biological activity (fibronectin-promoted cell spreading) was also greatest at low plasma concentrations and decreased as the plasma concentration was raised. When surfaces were exposed to plasma under clotting conditions (i.e., addition of Ca2+ and thrombin), fibronectin deposition on the surfaces and biological activity remained constant or increased as the plasma concentration was raised. Based on indirect immunofluorescent antibody assays, the fibronectin deposited from clotting plasma appeared to be in a punctate distribution over the entire material surface and occasionally was associated with discrete fibrillar structures. The increased deposition of fibronectin from clotting plasma compared to nonclotting plasma (approximately a 10-fold difference with 10% plasma) was partially a result of covalent crosslinking of fibronectin to fibrin based upon studies with putrescine added to inhibit crosslinking during clotting. On the other hand, the increase in biological activity that occurred if the surfaces were exposed to clotting plasma was completely inhibited by putrescine, indicating that fibronectin had to be crosslinked to fibrin to have biological activity under these conditions. Finally, fibronectin deposition also occurred on surfaces exposed to whole blood and was markedly enhanced when clotting occurred.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1041160305
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