FIGURE 1.
Summarized effects of recombinant Ace stimulation on Cl− current in Caco-2 cell monolayers. A, representative time course of changes in Isc and the effect of different doses of apically applied Ace on the changes in Isc (insets). Each concentration of Ace was added as a single dose to separate monolayers. Values are means ± S.E. n = 3–5. NS, statistically not significant. B, effects of basolateral bumetanide (100 μm) on basal and Ace (1 μm)-stimulated Isc. Summary of data showed average ΔIsc in response to Ace in the absence (−) or presence (+) of bumetanide. Values are means ± S.E. n = 4. C, effects of Ace on apical ICl. After establishment of a basolateral-to-apical Cl− gradient in the high K+ solution by depolarizing the basolateral membrane, addition of Ace (1 μm) evoked an outward current consistent with a secretory Cl− flow from the basolateral-to-apical side. Summary data show the change in ΔICl induced by Ace stimulation. Values are means ± S.E.; n = 5. Error bars represent S.E. *, significant difference compared with control (unpaired t test).