Intestinal transport of fructose and glycine in Ophiocephalus punctatus.

The regional variations in the absorption of fructose and glycine have been studied in the intestine and pyloric caeca of the fish, Ophiocephalus punctatus in vivo, by preparing intestinal sacs. Diffusion of amino acids out of the intracellular compartment of the intestine was observed in all the portions of the intestine. The pyloric caeca showed maximum transport of fructose. Absorption of fructose was slightly more in the posterior intestine than in the anterior intestinal sac. Maximum transport of glycine took place in the anterior intestinal sac. Pyloric caeca adsorbed more glycine than did the posterior sac. For both nutrients, the rate of uptake did not differ significantly in the upper and the lower portion of the intestine. In all the portions, the transport of fructose was more rapid than that of glycine. The experiments revealed that though the nutrients are absorbed in the entire length of the intestine, the quantity absorbed varies from one portion to another and is dependent on the nature of the compound absorbed.