Figure 3.

Effects of kinase inhibitors on I_Eq. In each experiment, V_t and R_t were recorded simultaneously from pairs of age-matched cells at identical passage and the arrows indicate the addition of either the appropriate test substances or solvent vehicle (control) to the apical and basolateral baths. After 30 min, cells were exposed to insulin (20 nM, basolateral, shaded areas) and experiments were finally terminated by adding 10 µM amiloride to the apical bath (right hand arrows, Amil). Once recordings were complete, values of I_Eq were calculated, normalized to the magnitude of the basal current measured at the onset of the experiment and presented as mean ± SEM. (A) Effects of wortmannin (0.1 µM); basal I_Eq (control): –27.5 ± 2.7 µA·cm⁻²; basal I_Eq (test): –25.4 ± 3.6 µA·cm⁻²; (n = 5). (B) Effects of PI103 (1 µM); basal I_Eq (control): −26.1 ± 5.0 µA·cm⁻²; basal I_Eq (test): –30.0 ± 6.1 µA·cm⁻²; (n = 6). (C) Effects of GDC-0941 (1 µM); basal I_Eq (control): –20.7 ± 1.3 µA·cm⁻²; basal I_Eq (test): –20.9 ± 3.3 µA·cm⁻²; (n = 5). (D) Effects of rapamycin (0.1 µM); basal I_Eq (control): −27.8 ± 3.4 µA·cm⁻²; basal I_Eq (test): –23.3 ± 4.1 µA·cm⁻²; (n = 5).