The Movement of an Unemulsified Oil Test Meal and Aqueous‐and Oil‐phase Markers Through the Intestine of Normal and Bile‐diverted Rats

Abstract

An unemulsified oil test meal containing aqueous- and oil-phase markers (PEG and 3-H labelled triether) was fed to control and bile fustula rats. PEG moved ahead of the lipid phase in all groups, and was of limited value as a marker for the test meal. Triether was an excellent marker for studies of gastric emptying. An unexpectedly high correlation was seen between the triether and the test meal and its digestion products in the intestine. The results suggest that triether is a valid marker for following the movement of lipid through the bowel under the conditions of this study. Triether/fat ratios indicated that fat absorption occurred largely from the upper small bowel in control animals and from the lower small bowel in the absence of bile. Bile diversion resulted in more rapid gastric emptying initially, but very slow gastric emptying of the last part of the oil test meal. Intestinal transit of test meal or either marker was not significantly affected by bile diversion. No evidence for a direct effect of bile diversion on gastrointestinal motility was found.

Intestinal absorption and postabsorptive metabolism of linoleic acid in rats with short-term bile duct ligation

“…The plasma concentrations of either [ 13 C]linoleic acid or [ 13 C]palmitic acid were significantly decreased in BDL rats compared with controls. Given the relative preservation of linoleic acid absorption measured by balance techniques (Table 2), it can be speculated not only that the absorption is not limited to the proximal segments of the intestine of BDL rats but also that more distal segments are involved in its absorption, giving rise to altered plasma kinetics (3,4). To exclude the (theoretical) possibility that absorbed linoleic acid would be distributed differently over the various lipid classes in plasma (for example, triacylglycerols, phospholipids, free fatty acids), an analytical method was applied in which all fatty acids present in plasma, either esterified or unesterified, were determined simultaneously in a pooled fashion.…”