STUDY OF ENERGIZED TRANSPORT MECHANISMS OF GLYCINE ABSORPTION BY THE RAINBOW-TROUT (SALMO-GAIRDNERI RICHARDSON)

1. 1. The effects of metabolic inhibitors on in vitro glycine absorption and net water fluxes were studied. Previous controls of oxygen uptake by poisoned intestines were performed. 2. 2. A slight inhibition of glycine absorption was induced by NaF (5 × 10-3 M) or 2:4 DNP (10-5 M) in midgut or hindgut, especially when the saline was devoid of Ca2+ and Mg2+ (NaF). NaF caused a reversion of net water fluxes. 3. 3. Anoxia resulted in an important inhibition of glycine absorption and in a complete reversion of net water fluxes. 4. 4. The effects of 2:4 DNP and anoxia were minimized when the saline was devoid of Na+. Furthermore, ouabain strongly depressed glycine absorption. 5. 5. These experiments indicate that in trout, as in mammals, glycine transport is achieved by active processes coupled with Na+-K+ gradients. © 1979.