Selective expression of brush border hydrolases by mouse Peyer's patch and jejunal villus enterocytes.

Developmental profiles describing the expression of lactase, alpha-glucosidase, and alkaline phosphatase activities have been determined quantitatively in mouse jejunal enterocytes during migration over villi and Peyer's patch lymphoid tissue. The predicted maximal lactase and alpha-glucosidase activities expressed by enterocytes migrating over Peyer's patch follicles were about one-quarter and one-half of values found in control villi. Alkaline phosphatase activity was, on the other hand, one third greater in Peyer's patch compared with villus enterocytes. Expression of lactase and alpha-glucosidase activities was initially less in enterocytes migrating along interfollicular compared with control villi. Subsequent increase in hydrolase activities occurred during the later stages of enterocyte migration over interfollicular villi. Lactase activity in athymic mice Peyer's patch enterocytes was identical to that recorded for control mice. The corresponding value for villus lactase was, however, only half that found in control tissue. Factors produced locally in lymphoid follicles are probably responsible for selective effects on enterocyte differentiation.