Platelet-endothelial interaction during tumor angiogenesis.

Platelet-endothelial interaction is not an intense phenomenon during tumor angiogenesis. Platelet rolling was increased on day 1 in pre-existing microvessels of the host in response to both LLC-1 (▪) and BFS-1 () and also on day 3 in LLC-1 tumor microvessels, but was only slightly above the low baseline level quantified in postcapillary venules of controls (■). Median ± standard error of the median; n = 6 experimental animals per group. *P < .05 versus controls; #P < .05 versus day 1; ¶P < .05 versus day 3 (Kruskal-Wallis test).