Fig. 3.

Effect of chronic hyperinsulinemia on insulin- and nutrient-signaling pathways in the fetal liver. A: protein expression was measured by Western blotting in liver samples of control (CON) and hyperinsulinemic (INS) fetuses for IRb and Akt and for phosphorylated and total mammalian target of rapamycin (mTOR; S2448), S6K (S421, T424), S6 (S235/S236), and ERK (T202/Y204). B: results were quantified for IRb and Akt expression and normalized to actin. C: results were quantified, and the ratio of phosphorylated to total protein was calculated for mTOR, p70, S6, and ERK. D: expression of genes involved in insulin signaling in the fetal liver. Means ± SE are shown (n = 8 CON and 7 INS). *P < 0.05 in CON vs. INS. INSR-A and INSR-B, insulin receptor genes A and B, respectively; TAT, tyrosine aminotransferase.