ACIDIC AND BASIC FIBROBLAST GROWTH-FACTORS HAVE COMPARABLE EFFECTS ONTHE HEMOSTATIC FUNCTION OF VASCULAR ENDOTHELIUM

Acidic and basic fibroblast growth factor (aFGF and bFGF respectively) are closely related mitogens (55% homology) of the heparin binding gr owth factor family. Reports of the relative potency of these growth fa ctors and the ability of heparin to potentiate the activity of bFGF ar e conflicting. We have examined the effect of heparin and human recomb inant aFGF and bFGF on basal and thrombin challenged release of metabo lites from cultured human umbilical vein endothelial cells (HUVEC). Cu lture supernatant was assayed for thrombospondin, prostacyclin and PAI -1 and cell lysates were analysed for t-PA. aFGF and bFGF were equipot ent in regulating the release of all metabolites studied, except throm bin stimulated release of PGI(2) where bFGF was more potent than aFGF in the absence of heparin. Heparin potentiated the mitogenic and metab olic effects of both bFGF and aFGF. However, heparin was not essential for the expression of the biological activity of FGF.