Fig. 7.

A: the effect of ouabain on cAMP in control cells and in cells subjected to 20 mM ammonium chloride exposure for 5 min followed by a 2.5-min recovery period in Krebs solution. Treated cells received ouabain (1 μM or 1 mM) throughout the experiment. B: the effect of forskolin on cAMP. Cells were treated with forskolin (10 μM) or ouabain (1 μM) without exposure to ammonium chloride. Values are means ± SE of results from 4 independent experiments. **P < 0.01, ***P < 0.001, significant difference from control where experiments were conducted without ammonium chloride treatment. #P < 0.05, ##P < 0.01, significant difference from control where the cells were treated with ammonium chloride.