Figure 3.

Dose-dependent effects of PRL and glucocorticoids on gene expression in INS-1 cells. INS-1 cells were incubated for 20 h in serum-free basal medium in the presence or absence of rat PRL (10–500 ng/ml, 0.4–20 nm), DEX (0.02–1 μm, 20–1000 nm), hydrocortisone (HC; 15–60 μg/dl, 410–1640 nm), or diluent. mRNA levels were measured by quantitative PCR. Values in diluent-treated control cells were adjusted so that the mean equaled 1.0; values for hormone-treated cells were calculated as a function of the mean of control values. The figure shows the mean ± sem of four flasks per treatment group. PRL had statistically significant effects (P < 0.01) on gene expression at concentrations exceeding 10 ng/ml (0.4 nm). DEX and HC had statistically significant effects (P < 0.001) on gene expression at all concentrations tested.