The effect of carotid occlusion on the rate of net fluid absorption in the small intestine of rats and cats.

The effect on net intestinal fluid absorption of unloading the baroreceptors by bilateral carotid occlusion was studied in rats and cats. It was shown that net fluid uptake from the intestine increased 30-40% upon carotid occlusion. This effect was eliminated by cutting the splanchnic nerves (cats) or by severing the nerves surrounding the superior mesenteric artery (rats). In fact, these denervation procedures resulted in a decreased net fluid absorption upon carotid occlusion. Cutting the vagal nerves did not significantly influence the response to carotid occlusion. It is concluded that the arterial baroreceptors influence net fluid transport in the small intestine, a reflex compensatory mechanism that may be important in different hypotensive situations.