Fig. 4

Effects of LY294002 (LY, a PI3K inhibitor, 30 μM) (a) and PD98059 (PD, a MEK inhibitor, 50 μM) (b) on insulin-induced mRNA expression of the NKCC and the CFTR Cl⁻ channel. After pretreatment with or without LY294002 or PD98059 for 1 h in the culture medium, A6 monolayers were incubated in the culture medium with or without 1 μM insulin in the presence or absence of LY294002 or PD98059 for 6 h. The mRNA expression of NKCC and CFTR was detected by real-time PCR. Relative amounts of mRNA expression of NKCC and the CFTR Cl⁻ channel were normalized to β-actin as an internal control. Amounts of mRNA expression of NKCC and the CFTR Cl⁻ channel in the absence of insulin are shown as 1.0; therefore, the relative amounts of mRNA expression of NKCC and the CFTR Cl⁻ channel shown here mean the insulin action on amounts of mRNA expression of NKCC and the CFTR Cl⁻ channel compared with those without insulin pretreatment. Data are presented as mean ± SEM. n = 5–8. NS, no significance; *p < 0.05