Table 2. Effect of preincubation with tetrodotoxin (TTX, 0.1 µmol/L) or 6-hydroxydopamine (6-OHDA, 1.46 mmol/L) on the frequency–contraction curves performed in control, ketotifen-incubated (0.1 µmol/L) and tranilast-incubated (0.1 mmol/L) mesenteric segments.
| 1 Hz | 2 Hz | 4 Hz | 8 Hz | 16 Hz | |
|---|---|---|---|---|---|
| Control | 9.2 + 1.7 | 27.6 + 3.5 | 45.9 + 3.4 | 62.6 + 3.3 | 79.1 + 3.7 |
| TTX | 0 | 0 | 0 | 0.5 + 0.04 | 0.9 + 0.2 |
| 6-OHDA | 0 | 0 | 0.1 + 0.03 | 0.2 + 0.05 | 0.4 + 0.1 |
| Ketotifen | 17.8 + 1.7 | 34.9 + 4.1 | 53.5 + 4.8 | 69.6 + 3.8 | 90.1 + 2.6 |
| TTX | 0 | 0 | 0 | 0.2 + 0.01 | 0.6 + 0.1 |
| 6-OHDA | 0 | 0 | 0.2 + 0.06 | 0.5 + 0.1 | 0.9 + 0.2 |
| Tranilast | 2.5 + 1.1 | 7.0 + 3.1 | 21.3 + 6.1 | 39.9 + 8.2 | 61.5 + 8.7 |
| TTX | 0 | 0 | 0 | 0 | 0.1 + 0.01 |
Results (means ± S.E.M.) are expressed as percentages of the response elicited by 75 mM KCl; zeros are used when contraction was not detected. n = 5–7 animals.