Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: April 14, 1996
Publication Date: N/A
Technical Abstract: Some trace elements, such as Mn, Cu, and Zn, are absorbed and quickly resecreted into the gut through the bile. When this occurs, the unabsorbed nutrient, and the absorbed and resecreted nutrient may mix in the gut, preventing quantitative calculation of either. We have developed a surgical model which prevents this complication. Pigs (20-40 kg) were fitted with cannulas in the bile duct, lumen of the duodenum, portal vein, ileo-colic vein and jugular vein. Animals recovered for six to eight days and then were given an oral dose of 250 uCi of 54Mn. The flow rate of blood past the portal vein was determined by infusion of para-amino hippuric acid into the ileo-colic vein. Absorption was quantified by multiplying the concentration of 54Mn in the portal blood by the flow rate. Biliary excretion was determined by quantitative collection of bile, and previously collected bile was reinfused into the gut lumen. Urine and feces were also quantitatively collected. Six to eight days was sufficient time for animals to recover from the effects of surgery and anesthesia, as assessed by several measures of metabolic function, and food and water intake. True absorption was calculated to be 4.0%, as determined by the concentration of 54Mn in the portal blood. 54Mn in the urine and bile began to increase after 4 days. When the pig was euthanized after 12 days, only 0.5% of the 54Mn remained in the carcass.