Figure 5.

Calcein uptake by brain endothelial cultures in the presence or absence of P-gp and MRP-1 inhibitors (verapamil and MK-571, respectively). The results are expressed as mean ± SEM of duplicate batches of three independent cultures in the presence or absence of glioma cells from three different tumors listed in Table 1 (n = 3). Calcein-AM, brain endothelial cultures exposed to calcein-AM; Verapamil, brain endothelial cultures preincubated with verapamil; MK-571, brain endothelial cultures preincubated with MK-571; HUBEC, human brain endothelial cells; HUBEC + glioma, human brain endothelial cells in the presence of glioma cells. *HUBEC vs HUBEC + glioma, p = 0.025; **HUBEC vs HUBEC + glioma, p = 0.01; °HUBEC vs HUBEC + glioma, p = 0.0075 (paired t-test).