Figure 3. E2 inhibits Cl⁻ secretion in NuLi-1 cells.

NuLi-1 cells were cultured on collagen-coated culture inserts. The monolayers were then allowed to reach a transepithelial resistance of 1,000 Ω.cm⁻² or above prior the experiment. A. When mounted in the Ussing chambers, the cells were allowed to stabilize and were then treated basolaterally with E2. The changes in short-circuit current were then measured in response to amiloride (10 µM), ATP (100 µM), forskolin (10 µM) and bumetanide (10 µM). Typical traces of Isc in control and E2 treated NuLi-1 cells are shown. B. Summary of the amiloride short circuit current in control and E2 treated cells. Panel C shows ASLh measurement in NuLi-1 in response to estrogen and ENaC inhibition. NuLi-1 monolayers were treated with E2 (1 nM), Amiloride (Am, 300 µM) or pretreated with estrogen and then treated with amiloride (E2 + Am) (n≥3, error bars reflect standard error of the mean, ANOVA, ** p<0.01, *** p<0.001). Panels D and F show ASLh measurement in NuLi-1 epithelial cells after treatment with (D) E2 (30 min, 1 nM), Bumetanide (Bum, 30 min, 10 µM) or pretreated with E2 and then treated with Bumetanide (E2 + Bum) or (F) E2 (30 min, 1 nM), Forskolin (FSK, 30 min, 10 µM) or pretreated with E2 and then treated with Forskolin (E2 + FSK) (n≥5, Error bars reflect standard error of the mean, ANOVA, * p<0.05, ** p<0.01, *** p<0.001). Panel E shows bumetanide-sensitive current in NuLi-1 cells treated with E2 or with vehicle. Bumetanide was added after 30 minutes (n≥5, Error bars reflect standard error of the mean, Student's t test, * p<0.05).