Figure 2.

H₂S potentiates the effect of forskolin and IBMX. (a) Representative current traces of TEVC recordings of CFTR-expressing oocytes. Transmembrane currents (I_M) were recorded and oocytes were exposed twice to forskolin (fsk., 5 µM) and IBMX (100 µM, black bars) without or with application of Na₂S (arrowheads; concentration in µM is indicated by numbers in parentheses) between the first and second stimulation with forskolin/IBMX. (b) Representative current trace of a TEVC recording of a CFTR-expressing oocyte. Similar to experiments shown in panel a, oocytes were stimulated twice with forskolin/IBMX and Na₂S (50 µM) together with the CFTR inhibitor CFTR_inh172 (CFTR_inh., 25 µM) between the first and second application of forskolin/IBMX. (c) Statistical analysis of data obtained from experiments as shown in panel a. Depicted are values of I_M (peak values after drug application) from individual experiments (grey symbols) as well as means ± SEM, before and after application of Na₂S (*P ≤ 0.05, Student’s paired t-test). (d) Statistical analysis of data obtained from experiments as shown in panels a and b. Depicted are normalised values from individual experiments (grey symbols) as well as means ± SEM of forskolin (fsk.)/IBMX effects. This represents the ratio of the first and second current stimulated by forskolin/IBMX (**P ≤ 0.01, ***P ≤ 0.001, Kruskall-Wallis test followed by Dunn’s Multiple Comparison Test). Numbers of experiments (n) are indicated in parentheses.