Time course of the efflux of Hoechst33342.

<p>Cells were incubated with 3 µM Hoechst33342 in the presence of 10 µM of α-adrenoceptor antagonists (100 nM for ergot alkaloids) for 60 min at 37°C, washed twice with ice-cold HBSS and incubated with warmed HBSS in the presence of 10 µM of α-adrenoceptor antagonists (100 nM for ergot alkaloids) for the desired times. ○, HeLa; •, HeLa/SN100; Δ, HeLa/SN100+10 µM α-adrenoceptor antagonists (100 nM for ergot alkaloids). Each point represents the mean ± S.E. (n = 3), and error bars are included in the symbols. * and ** p<0.05 and 0.01 significantly different from the HeLa/SN100 cells in the absence of α-adrenoceptor antagonists at the corresponding time points, respectively.