Fig. 1.
ENaC is activated by SF. (A) Representative recording of SF application on αβγENaC currents in Xenopus oocytes. Activating the bath perfusion (0.2 dyn/cm2, orange bar) induced a rapid increase of the transmembrane current (IM). Amiloride (a, black bar) was applied to estimate ENaC-mediated current in the absence (I0) and presence (I0.2) of SF. (B) Current values with SF were normalized with respect to the values before SF was applied (I0.2/I0). (mean ± SEM; **P < 0.01, one-sample t test, two-tailed). (C) The SF-response (ISF) was augmented by increases in SF. (D) SF has no effect in the presence of amiloride (a, black bar, 10 µM), when ENaCs are blocked. (E) Neither SF nor amiloride affect endogenous ion channels of Xenopus oocytes. Oocytes were treated identical although no cRNA was dissolved in the water used for injection (representative traces of at least 12 recordings using oocytes from at least three different animals).