Active transport of C¹⁴-d-glucose by turtle small intestine

¹ Department of Biology, Saint Louis University, St. Louis, Missouri

An in vitro preparation was used to demonstrate that C¹⁴-d-glucose is taken up at the mucosal surface of turtle small intestine at 30 C. Movement of the sugar across the intestinal tissues and its release into the serosal fluid against an apparent concentration difference was shown. The source of the sugar entering the medium on the serosal side appeared to be, in part, the glucose taken up from the mucosal fluid, and, in part, some stored carbohydrate. Tissue analysis indicated the presence of a glycogenlike polysaccharide in the intestinal wall of both active and cold-torpid turtles. It was concluded that, during intestinal transport in Chrysemys picta, some of the glucose absorbed is converted to endogenous carbohydrate, or metabolized, and some is translocated.