Evidence for the facilitated diffusion of glucose into rabbit oviductal fluid.

Glucose movement into the oviductal fluid of rabbits was studied in anaesthetized animals. The oviducts were cannulated at each end, and 2 ml 0-9% NaCl at 37 degrees C were recirculated through the lumen for 4 h. D-Glucose appeared linearly in the fluid, reaching an average concentration of 2-6 mM. The rate of D-glucose appearance was 17 times greater than that of L-glucose, infused intravenously, suggesting that a component of the D-glucose movement operated by facilitated diffusion. The oviduct was unable to move glucose against an adverse plasma to lumen concentration gradient. We suggest that the glucose entering the oviductal fluid originates in the plasma and that the mucosal portion of the oviduct is responsible for this sugar transfer.