Fig 2.

IGF-1 inhibits expression of a GH promoter luciferase plasmid in MtT/S cells. The pGL4.11[lucP] vector containing a 2.7-kb fragment with the mouse GH promoter (pGL4-mGHp) was transfected into MtT/S cells overnight. After recovery, a subgroup of cells were treated with IGF-1 (30 nM) for various time periods. This experiment was also performed in cells transfected with pGL4.11[lucP] empty vector (pGL4-EV). Data are shown as the percent luciferase inhibition after IGF-1 treatment at each time point. Significant inhibition of luciferase expression was first noted at 24 h and persisted through the remaining time points. *, P < 0.05. Shown are means + SEM.