Table 2.
cAMP-stimulated Cl− efflux in CFTR cDNA-transfected IB3-1 CF cells
| cDNA transfected | n | Cl− efflux, % lost per min
|
Paired P value | |
|---|---|---|---|---|
| Before agonists | After agonists | |||
| Mock | 42 | 33.01 ± 3.12 | 29.53 ± 2.22 | NS |
| Wild-type | 37 | 22.99 ± 1.47 | 46.51 ± 6.53* | <0.005 |
| Δ259-M265 | 30 | 21.85 ± 1.43 | 47.67 ± 5.95* | <0.005 |
| Δ259-M265V | 18 | 24.55 ± 1.17 | 29.25 ± 2.23** | <0.05 |
| TMD-1 (K370X) | 24 | 16.63 ± 1.80 | 53.51 ± 9.50* | <0.005 |
| TMD-1 (K370EcoRV) | 24 | 19.54 ± 1.67 | 41.27 ± 5.22* | <0.005 |
| T-N-R | 18 | 19.21 ± 1.89 | 28.05 ± 3.35** | <0.05 |
| R334W-R347P | 18 | 19.85 ± 3.20 | 31.16 ± 6.79** | <0.05 |
| R334W-R347P-TMD-1 | 18 | 23.12 ± 2.60 | 26.26 ± 3.42 | NS |
The Before agonists value is the rate of 36Cl− efflux immediately prior to stimulation with cAMP agonists (2.5 μM forskolin, 250 μM CPT-cAMP, and 250 μM 8-bromo-cAMP). The After agonists value shown is the peak stimulated rate after addition of cAMP agonists. For mutants Δ259-M265V, T-N-R, and R334W-R347P, the magnitude of cAMP stimulation is significantly less (P < 0.05, versus paired control value as denoted by two asterisks) than that for the wild type and other responding mutants [Δ259-M265, TMD-1 (K370X), TMD-1 (K370EcoRV), P < 0.005 as denoted by one asterisk], as determined by ANOVA followed by the Bonferroni ad hoc test. NS, not significant.