Experimental Studies on the Intestinal Flow Using ⁵¹Cr as Indicator

Experiments were performed to illustrate whether the aspirated volume of intestinal content may serve as an adequate expression of the volume passing the site of aspiration, and whether the integrated intestinal flow (the fluid volume passing a definite section of the intestine in a given time) may be calculated with tolerable accuracy by means of infusion of a reference substance. In rabbits and dogs two tubes were inserted into the duodenum upon which isotonic glucose solution and physiological saline containing Na₂⁵¹CrO₄ were infused. The intestinal contents were aspirated through three tubes inserted 10-25 cm distally to the former. Aspiration of intestinal content through a single tube was found to vary greatly and to be far from complete. A weak and inconstant correlation between the aspirated volume and the volume passing the site of aspiration was found. The integrated intestinal flow calculated on the basis of the concentration of ⁵¹Cr in the aspirates from the different tubes provided considerable variations in the same subject. On an average the intestinal flow was calculated nearly 30 per cent too high. The error in calculation of intestinal flow was mainly attributed to incomplete mixing with uneven distribution of the infused reference substance in the intestinal content. It is concluded that the method is not applicable in estimating the integrated intestinal flow in the intact intestine.