Active transport of d-glucose in intestinal segments, in vitro, of the scup, Stenotomus versicolor and the puffer, Spheroides maculatus

Abstract

1. 1. Active transport of d-glucose was shown using intestinal sac preparations, in vitro, made from two marine fish, the scup, Stenotomus versicolor and the puffer, Spheroides maculatus. 2. 2. Differences in absorption characteristics were evident in populations from year to year. 3. 3. Anaerobiotic conditions, i.e. 100 per cent nitrogen gassing of the incubation medium, inhibit the active transport of d-glucose in scup and puffer intestine. 4. 4. Phlorizin, 5 × 10 −4 M, inhibits the active transport of d-glucose in scup intestine. 5. 5. Intestinal transmural glucose transport mechanisms operate well at incubation temperatures, 20°–27°C, i.e. temperatures close to habitat and holding tank temperatures, whereas movement of the sugar against a concentration gradient is interrupted at higher incubation temperatures, 29° and 30°C. 6. 6. Detailed comparison of procedures and results with those used by other workers in the field of in vitro intestinal absorption of poikilotherms suggests that aerobic metabolism may not be a uniformly significant energy source in intestinal active transport.