Table 1.
Mean (± SEM) Contractions Developed by Tissues in Response to Electrical Field Stimulation.
| Drug/frequency | Contraction (% of baseline) | Inhibition (% of control response) | ||
|---|---|---|---|---|
|
| ||||
| Absence of drug | Presence of drug | |||
| Guanethidine (10 μM, n = 7) | 5 Hz | 21.5 ± 10.3 | −9.0 ± 4.8a | 130.7 ± 47.2 |
| 10 Hz | 55.7 ± 17.3 | −8.2 ± 9.1a | 120.0 ± 18.7 | |
| Atropine (1 μM, n = 8) | 5 Hz | 31.1 ± 6.1 | 24.7 ± 7.9 | 10.0 ± 20.8 |
| 10 Hz | 46.4 ± 9.2 | 35.3 ± 7.3 | 13.6 ± 20.2 | |
| α,β-methylene-ATP (10 μM, n = 4) | 5 Hz | 33.4 ± 9.6 | 19.2 ± 7.4a | 44.8 ± 5.0 |
| 10 Hz | 42.5 ± 6.1 | 35.0 ± 7.8 | 20.4 ± 15.1 | |
a
P < 0.01 compared to responses in the absence of drug.
Responses are expressed as a percentage of the initial resting tone immediately prior to stimulation. In the presence of guanethidine only relaxation responses were observed (indicated by negative values).