Intestinal alkaline phosphatase: regulation by a strain-specific factor in mouse milk.

Two inbred strains of mice show a threefold difference in duodenal phosphatase activity at 11 days of age. When half-litters of the two strains are interchanged between the two mothers on the day of birth, enzyme activity in young of the low-activity strain is unaffected at 11 days by the source of milk, but is significantly reduced in high-activity young nursed by a low-activity mother.