FIG. 1.

Effects of insulin and glucose on ADD1/SREBP-1c gene expression in cultured hepatocytes. (A) Hepatocytes were cultured for 16 h in the presence of 5 mM glucose and then incubated for 6 h with or without insulin at a concentration of 1 to 100 nM in the presence of 5 mM glucose. A representative Northern blot as well as the quantification of blots obtained in three independent experiments is shown. (B) Hepatocytes were cultured for 16 h in the presence of 5 mM glucose and then incubated with 100 nM insulin for 1 to 6 h. (C) Hepatocytes were cultured for 16 h in the presence of 5 mM glucose and then incubated for 6 h with 5 or 25 mM glucose in the absence or presence of 100 nM insulin. Total RNAs were extracted and analyzed for the concentration of ADD1/SREBP-1c, FAS, and albumin mRNAs. The Northern blots are representative of three culture experiments. Statistical significance was analyzed by Student’s t test for unpaired data. When quantified, the concentrations of ADD1/SREBP-1c mRNA are expressed as a ratio to the corresponding albumin signal. ∗∗ and ∗∗∗, difference statistically significant for P < 0.01 and P < 0.001, respectively.