Table 1.
Transient contractions mediated by Ca2+ release in tracheal, bronchial and ileum SM permeabilized with α-toxin
| Material | Reagent | Dose (μm) | 50 μm GTP | Percentage of caffeine response | n |
|---|---|---|---|---|---|
| Tracheal SM | InsP3 | 100 | – | 0.1 ± 0.3 | 4 |
| cADPR | 10 | – | 0.2 ± 0.3 | 4 | |
| CCh | 1 | + | 96.3 ± 5.5 | 4 | |
| Bronchial SM | InsP3 | 100 | – | 32.5 ± 9.1 | 12 |
| cADPR | 10 | – | −3.7 ± 2.0 | 4 | |
| CCh | 1 | + | 85.6 ± 14 | 5 | |
| Ileum SM | InsP3 | 300 | + | 105 ± 12 | 3 |
| cADPR | 300 | + | 0.5 ± 0.7 | 3 | |
| CCh | 1 | + | 102 ± 6.5 | 3 |
Rabbit tracheal smooth muscle (SM), human bronchial SM and guinea-pig ileum longitudinal SM were studied. InsP3, inositol 1,4,5-trisphosphate; cADPR, cyclic ADP ribose; CCh, carbachol; GTP, guanosine triphosphate. The amplitudes of the caffeine (30 mm) responses of tracheal, bronchial and ileum SM strips were 0.8 ± 0.12 mN (n = 4), 0.5 ± 0.21 mN (n = 12) and 0.8 ± 0.12 mN (n = 3).