Interleukin-15 decreases lipid intestinal absorption

Administration of a single acute intravenous injection of interleukin-15 (IL-15) (100 µg/kg bw) to rats resulted in a significant decrease (22%) in triacylglycerol absorption, as measured by using [14C]-triolein load. The cytokine, however, did not influence the oxidation of the exogenously administered lipid or the tissue uptake of [14C]-triolein; this is in concordance with the lack of effects found in the measurement of the tissue lipoprotein lipase activity. Concerning the mechanism involved in the decreased intestinal absorption associated with IL-15 administration, the results presented clearly demonstrate that changes in gastric emptying and intestinal mobility are not involved, as the effect is specific for triacylglycerols. In conclusion, intestinal absorption may be an additional mechanism to take into consideration to explain the ‘anti-fat’ effect of this cytokine.