Absorption of thiamine from intestine of dog

Abstract

A chronic Thirty fistula of the jejunum and ileum was prepared which permitted repeated quantitative studies to be made on the absorption of various substances. Dogs weighing an average of 20 kg had an average intestinal capacity to absorb approximately 22 mg of thiamine per day, when the daily oral intake was 40 mg. Thiamine was not destroyed when incubated for 12 hr in vitro with the normal saline wash of a Thiry loop of the jejunum or ileum. It was mechanically possible to recover all the thiamine introduced into the Thiry loops within 30–60 sec after its introduction. The same amount of thiamine was absorbed from the jejunum and ileum, respectively, during 1 hr. In nine daily tests an average of 3.2 mg or 30% (range 18–40%) of 10 mg of thiamine in 20 ml of normal saline was absorbed in 1 hr, the loops being 25–30 cm long. When 20 ml of an aqueous solution containing 0.7% Na2SO4, 0.45% NaCl, and 0.1% glucose was introduced for 30 min, the ileal and jejunal loops absorbed all the glucose. The ileal loops absorbed 34 mg or 38% of chloride expressed as NaCl, whereas the jejunal loops apparently added chloride.