Changes in glycolytic enzyme activity in the duck (anas platyrhynchos) nasal gland during the period of adaptation to salt water

• 1.

  1. Activities of various enzymes were measured in birds drinking fresh water and in birds adapting to 200 mM salt water.

• 2.

  2. Although an increase in the activity of all enzymes was measured in ducks on salt water as compared to their freshwater controls, the probable rate limiting enzyme, phosphofructokinase, showed the greatest increase (three- to fourfold).

• 3.

  3. The correlation between the changes of the ATPase and phosphofructokinase enzyme activities supports the idea that the glycolytic pathway plus associated cycles supply a major proportion of the ATP needed by the transport enzyme.