Figure 8.

Effect of exogenous gangliosides and related compounds on the mitogenic activity of FGF-2 in endothelial cells. Subconfluent cultures of GM 7373 cells were incubated for 24 h at 37°C with 10 ng/ml FGF-2 in the presence of increasing concentrations of asialo-GM₁ (○), GM₁ (•), GD_1b (▵), GT_1b (□), galactosyl-ceramide (▪), or sulfatide (♦) (panel A) or of GM₂ (⋄), GM₃ (▿), NeuAc (□), N-acetylneuramin-lactose (▪) (panel B). At the end of incubation, cells were trypsinized and counted in a Burker chamber. For the different experimental conditions, data have been calculated as cell population doublings during the 24-h incubation period and expressed as percentage of the mitogenic activity exerted by FGF-2 in the absence of any competitor (equal to 0.8 cell population doublings, see also Figure 9A). Each point is the mean of two to six determinations in duplicate. SEM never exceeded 16% of the mean value.