Effect of amiloride, isoproterenol and ATP on intact excised rat trachea and cultured rat tracheal epithelial cell electrophysiology
| Intact Tracheas (n = 19) | Cultured Cells (n = 8) | |
|---|---|---|
| Baseline values | ||
| Voltage (mV) | −3.58 ± 0.36 | −19.9 ± 8.6 |
| Resistance (ohm.cm2) | 49.0 ± 2.3 | 148.4 ± 32.1 |
| Current (μA/cm2) | 71.6 ± 5.3 | 122.0 ± 26.5 |
| Changes | ||
| Δ Voltage (mV) | ||
| Amiloride | 0.20 ± 0.02 | 1.23 ± 0.32 |
| Isoproterenol | −0.66 ± 0.11 | −0.13 ± 0.41 |
| ATP | −2.70 ± 0.43 | −1.22 ± 0.32 |
| Δ Resistance (ohm.cm2) | ||
| Amiloride | 0.95 ± 0.16 | 4.24 ± 2.34 |
| Isoproterenol | −0.38 ± 0.16 | −31.81 ± 15.56 |
| ATP | −4.65 ± 0.94 | −41.53 ± 11.85 |
| Δ Current (μA/cm2) | ||
| Amiloride | −5.35 ± 0.54 | −8.53 ± 1.83 |
| Isoproterenol | 13.23 ± 2.15 | 30.75 ± 11.97 |
| ATP | 67.58 ± 10.19 | 65.47 ± 12.48 |
Amiloride (0.1 mM final concentration), isoproterenol (0.01 mM final concentration) and ATP (0.1 mM final concentration) were sequentially added to the apical chamber at 3-min intervals and electrical parameters were measured as described in “Methods.” All measurements were found to be significantly different from baseline (P < .05). Data are presented as means ± S.E.M.