Figure 2.Effect of intracellular cAMP stimulation on bicarbonate secretion, Isc and transepithelial conductance in CF muri ne duodenum. In pH stat experiments (2a) performed under voltage-clamped conditions, stimulation of intracellular cAMP with a forskolin/IBMX cocktail induces simultaneous increases in the serosal-to-mucosal flux of bicarbonate (Jsm HCO 3) and the Isc. However, the transepithelial conductance, Gt, was significantly increased by stimulation of cAMP (Basal Gt = 45.2 ±0.7; cAMP Gt = 553 ± 0.7, p < 0.05, n = 10). * Significantly different from Basal, p < 0.05). To estimate the effect of transepithelial conductance (2b) on the Jsm HCO 3, the DGt from the CF mice experiments were regressed against the DJsm HCO 3.