Abstract
1. The effect of zinc deficiency on the activities of rat duodenal alkaline phosphatase and inorganic pyrophosphatase has been investigated.2. Zn deficiency adversely affected the activity of these enzymes before growth rate and food intake were reduced.3. The level of food intake was without effect on the activity of alkaline phosphatase but markedly influenced that of inorganic pyrophosphatase.4. The relevance of changes in the activities of Zn-dependent intestinal enzymes to the food intake of Zn-deficient rats is discussed.