Inhibition of rat or rabbit colonic Cl− secretory response [ΔIsc (μA/cm2)] induced by H2O2, anti-IgE or FMLP (rabbit) with PAF antagonists, INDO alone or combinations of PAF antagonist, INDO and diphenhydramine
| Agonist | Maximum ΔIsc control response (n) | INDO 10−6 M | WEB 2086 10−4M | BN 52021 10−4 M | Ro 24-0238 10−5 M | Ro 24-4736 10−6 M |
|---|---|---|---|---|---|---|
| μA/cm2 | % of Control response | |||||
| H2O2 | ||||||
| Peak 12-e | 65 ± 13 (5) | 21 ± 5 | 61 ± 162-a | 38 ± 72-a | 15 ± 162-a | 49 ± 42-a |
| +INDO2-f | 36 ± 142-c | 13 ± 42-c | 3 ± 42-c | 12 ± 62-c | ||
| Peak 22-e | 46 ± 6 (5) | 53 ± 62-a | 73 ± 21 | 48 ± 112-a | 17 ± 92-a | 77 ± 42-a |
| +INDO2-f | 87 ± 18 | 43 ± 12 | 1 ± 42-c | 43 ± 112-c | ||
| Anti-IGE | 51 ± 14 (6) | 50 ± 72-a | 62 ± 122-a | 52 ± 142-a | 36 ± 122-a | 43 ± 102-a |
| +INDO2-f | 51 ± 29 | 31 ± 13 | 19 ± 12 | 25 ± 14 | ||
| +INDO + DPHd | 3 ± 42-b | 13 ± 72-b | ||||
| FMLP2-e | 64 ± 2 (6) | 13 ± 82-a | 92 ± 9 | 86 ± 1 | 49 ± 92-a | 95 ± 20 |
| +INDO2-f | 8 ± 52-c | 7 ± 72-c | 12 ± 82-c | 10 ± 112-c | ||
↵2-a P < .05 agonist vs. agonist + antagonist or INDO.
↵2-b P < .05 agonist + antagonist vs.agonist + antagonist + INDO + diphenhydramine.d
↵2-c P < .05 agonist + antagonist vs.agonist + antagonist + INDO.
↵2-e The percentage of control response on this line refers to the inhibition observed with INDO alone or with the PAF antagonist alone.
↵2-f The percentage of control response on this line refers to the inhibition observed with a combination of INDO and the PAF antagonist.
INDO, 10−6 M; diphenhydramine, 10−6 M; FMLP, 10−7 M; H2O2 500 μM; anti-IgE 90–120, μg of protein/ml.