Figure 3. Abnormal calcium responses in CFTR–deficient muscle cells.

(A) Negative immunostaining for CFTR in Cftr ^−/− myotubes. (B) Representative Ca²⁺ responses in Cftr^+/+ myotubes, either without (control) or with (CFTR-inh) pre-treatment by CFTR-inh172. (C) Representative Ca²⁺ responses in Cftr^+/+ versus Cftr ^−/− myotubes. (D) Lack of effect of CFTR-inh172 on the area under the curve or peak amplitude of Ca²⁺ responses in Cftr ^−/− myotubes.