Summary of the results of the study. Four variables were studied: villus morphology, luminal myeoloperoxidase activity (MPO), the presence of red blood cells (RBC) in intestinal veins, and accumulation of Evan's blue in the intestinal tissue. The effects of the different experimental procedures were judged compared with observations made in control experiments performed on acutely denervated intestines. Experiments were carried out using a low (1 μg/ml) or high (15 μg/ml) concentration of Clostridium difficile toxin A. Hexamethonium (Hex) and nifedipine (Nif) experiments were performed on acutely denervated (dener.) intestinal segments
| Low toxin | High toxin | ||||
|---|---|---|---|---|---|
| Hex | Nif | Chronic dener. | Chronic dener. | ||
| Morphology | − | 0 | − | 0 | |
| MPO | − | − | 0 | 0 | |
| RBC | − | − | − | − | |
| Evan's blue | 0 | 0 | 0 | 0 | |
−, attenuation of response to toxin A; 0, no effect on response to toxin A.