TABLE 1.
Threshold concentration, potency (pEC50) and maximal effect (Emax) of (a) AVP and OT, for increasing muscle tone, amplitude and frequency of spontaneous contractions of human proximal and distal stomach circular muscle; (b) data for effect of adrenaline on spontaneous and EFS‐evoked contractions of human proximal and distal stomach
| (a) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Proximal | Distal | |||||||||||
| AVP | OT | AVP | OT | |||||||||
| Effect | Threshold (M) | pEC50 | Emax (%) | Threshold (M) | pEC50 | Emax (%) | Threshold (M) | pEC50 | Emax (%) | Threshold (M) | pEC50 | Emax (%) |
| Tone | 10−11–10−10 | 9.5 ± 0.2 | 7.1 ± 0.2 | 10−9–10−8 | 7.5 ± 0.0 | 4.4 ± 0.1 | 10−11–10−10 | 9.5 ± 0.1 | 9.5 ± 0.2 | 10−9–10−8 | 7.1 ± 0.1 | 6.3 ± 0.12 |
| Amplitude | 10−11–10−10 | 9.5 ± 0.1 | 244.8 ± 3.9 | 10−8 | 7.2 ± 0.1 | 145.6 ± 2.3 | 10−10 | 9.0 ± 0.1 | 55.0 ± 2.0 | 10−9–10−8 | 7.4 ± 0.1 | 51.5 ± 1.5 |
| Frequency | 10−11–10−10 | 8.9 ± 0.1 | 30.4 ± 2.6 | 10−9–10−8 | 7.4 ± 0.1 | 30.0 ± 2.6 | 10−11–10−10 | 9.0 ± 0.1 | 33.6 ± 1.0 | 10−9–10−8 | 7.2 ± 0.2 | 30.5 ± 2.5 |
| (b) | |||||
|---|---|---|---|---|---|
| Proximal | Distal | ||||
| Experimental condition | Effect | pEC50 | Emax (%) | pEC50 | Emax (%) |
| Baseline conditions | Tone (contraction) | 9.5 ± 0.2 | 6.3 ± 0.5 | 9.3 ± 0.1 | 7.6 ± 0.5 |
| Tone (relaxation) | 5.1 ± 0.2 | 100 | 5.1 ± 0.2 | 100 | |
| Amplitude | 8.6 ± 0.1 | 244.3 ± 10.2 | 8.7 ± 0.1 | 56.4 ± 3.8 | |
| Frequency | 7.6 ± 0.4 | 23.4 ± 1.9 | 8.1 ± 0.4 | 25.2 ± 1.2 | |
| EFS conditions | Tone (contraction) | 8.9 ± 0.1 | 5.1 ± 0.3 | 9.0 ± 0.1 | 6.4 ± 0.4 |
| Tone (relaxation) | 5.4 ± 0.2 | 100 | 4.8 ± 0.1 | 100 | |
| EFS‐evoked contraction inhibition | 5.9 ± 0.2 | 58.8 ± 4.9 | 6.2 ± 0.1 | 73.4 ± 4.0 | |
Note: Data are mean ± SEM. (a) n = 5. (b) n = 4.
Abbreviations: AVP, arginine vasopressin; EFS, electrical field stimulation; OT, oxytocin.