Effect of hirudin on release of GFP-labeled B16F10 or 4T1 cells into the blood. Hirudin and GFP-labeled B16F10 cells (A; 1 × 106) or 4T1 cells (B; 1 × 105) were injected into mice, as described in Figure 5, except for 10 days of hirudin treatment after tumor implantation. Blood was removed on days 10, 15, 20, and 30 and assayed for GFP-labeled cells by flow cytometry. ▪ indicates PBS-treated mice; ▦, hirudin-treated mice. (C) Effect of hirudin concentration on release of GFP-labeled B16F10 cells into the blood. Tumor was injected and mice treated with varying concentrations of hirudin. Blood was collected on day 15 and assayed for GFP-labeled cells. Numbers on curve refer to volumes of the tumor at day 15 of each of the 7 animals studied. (D) Number of viable tumor cells in the lung following 7 days of ex vivo culture of mice.
