Distinct Action of Flavonoids, Myricetin and Quercetin, on Epithelial Cl− Secretion: Useful Tools as Regulators of Cl− Secretion
Figure 3
NPPB-sensitive Isc. The NPPB-sensitive Isc was measured as the difference of Isc just before and 30 min after addition of 100 μM NPPB to the apical solution. for DMSO, for quercetin, and for myricetin without forskolin ((−) FK). for DMSO, for quercetin, and for myricetin with forskolin ((+) FK). Under basal conditions ((−) FK), the values of quercetin-stimulated Isc () and myricetin-stimulated NPPB-sensitive Isc () were significantly larger than the NPPB-sensitive Isc with DMSO alone (solvent control; ). The value of Isc with DMSO alone under forskolin-stimulated conditions (DMSO marked with § in (+) FK) was significantly larger than that with DMSO alone under basal conditions (DMSO in (−) FK; ). Under forskolin-stimulated conditions ((+) FK), the value of quercetin-stimulated Isc (Quercetin in (+) FK marked with #) was significantly smaller than that with DMSO alone (DMSO in (+) FK; ). On the one hand, under forskolin-stimulated conditions ((+) FK), the value of myricetin-stimulated Isc (##) was significantly larger than that with DMSO alone (DMSO in (+) FK; ). The value of quercetin-stimulated Isc was identical irrespective of forskolin stimulation (Quercetin in (−) FK versus Quercetin in (+) FK; NS, no significant difference), while the value of myricetin-stimulated Isc under forskolin-stimulated conditions (Myricetin in (+) FK) was significantly larger than that under basal condition (Myricetin in (−) FK; ).
