Figure 4. Afatinib does not affect calcium or cAMP signaling.

(A) (Left) cytoplasmic Ca²⁺ concentration measured by Fluo-4 fluorescence. Afatinib (20 μM) was added 20 minutes before addition of 100 μM ATP or 100 μM carbachol. (Right) peak increase in Fluo-4 fluorescence after ATP or carbachol (mean ± SEM, n = 4–6). (B) cAMP in T84 cells measured 30 minutes after incubation with afatinib (20 μM) or forskolin (20 nM, 90 nM, 20 μM), with or without afatinib (20 μM) (mean ± SEM, n = 3–6). Not significant, by 2-tailed t test.