Studies on the movement of glucose, pyruvate and lactate into the ampulla and isthmus of the rabbit oviduct.

The appearance of glucose, pyruvate and lactate in fluid recirculated through the lumen of the ampulla and isthmus of the rabbit oviduct has been followed for 2 h in vivo. Each nutrient appeared in the lumen of the ampulla at approximately 1.8 times its rate in the lumen of the isthmus. The circumference of the mucosa lining the two regions was measured together with the distribution of ciliated and secretory cells. The surface area of the mucosa lining the ampulla was 343 mm2, and that lining the isthmus, 191 mm2. It is tentatively suggested that the capacity of the ampulla and isthmus to transport small molecules is a function of their respective mucosal surface areas.