Fig. 6. Differential effect of CXP I silencing on early and late secretory phases. INS-1 cells were transiently cotransfected with a plasmid encoding hGH and with the empty pSUPER vector and siRNA CPX I. After 3 days, the cells were incubated under basal condition (Basal) or in the presence of 20 mM glucose. After 10 minutes, the incubation medium was collected and replaced with fresh buffer for an additional 35-minute period. Cellular hGH content and the fraction of hGH released by the cells during the first 10 minutes of incubation (top panel) and during the successive 35 minutes (lower panel) were measured by ELISA. The figure shows the mean ± s.e.m. of at least three independent experiments measured in triplicate (*P<0.01, ***P<0.001).