Fig. 2. C6-CM protective effect is time dependent. BBMEC monolayers were incubated with MEM/F12 or C6-CM for 1 or 3 days of exposure. Under normoxic conditions, neither 1 nor 3 days of exposure to C6-CM had any effect on monolayer permeability. However, after 24 hours of hypoxic stress, both 1 and 3 days of C6-CM exposure protected against hypoxia-induced monolayer breakdown. This effect was time dependent, with 1 day exposure being partly protective, and 3 day exposure resulting in almost complete protection against hypoxic stress. ^***P<0.001 versus a comparable normoxic treatment group, ^###P<0.001 versus hypoxic MEM/F12, ^{^}P<0.01 versus hypoxic 1 day C6-CM, n=4-8.