The significance of sympathetic nervous activity for the development of the intestinal mucosal lesions in shock.

A 2-hour period of regional hypotension at 30-35 mmHg in the feline small bowel was produced by partial occlusion of the superior mesenteric artery. In one series of animals the sympathetic fibres in the splanchnic nerves were stimulated bilaterally at 6 Hz throughout the hypotension. In another group of animals no such stimulation was performed on the denervated intestinal segments. A mucosal damage was observed in both series and it was graded histologically according to Chiu et al. (1970). The two groups were also compared as regards the magnitude of the blood pressure fall occurring during the first hour after the period of intestinal hypotension. No statistically significant difference could be demonstrated between the two series of experiments with regard to mucosal damage or blood pressure fall. It is hence concluded that sympathetic nervous activity does not contribute to any measurable extent to the development of mucosal damage and cardiovascular deterioration observed in connection with regional intestinal hypotension. The explanation for this is discussed.