Abstract
Using an antibody against rat intestinal alkaline phosphatase (ALP), the effects of intestinal cholera toxin (CT) administration on the localization and turnover of ALP in the intestinal epithelial cells in rats were assessed.
Immunohistochemical study revealed that the localization of ALP was mainly on the microvillus membrane and Golgi apparatus in control rats. In CT-treated rats, greater amounts of ALP positive membrane components were observed around the microvillus region as compared to those of controls. In turnover study of ALP, the incorporation of 3H-leucine into ALP molecules which were precipitated by the antibody against rat intestinal ALP was significantly increased on brush border membrane and in intestinal luminal contents after CT administration. However, incorporation of 3H-leucine into TCA-precipitated mucosal homogenate and brush border membrane was not altered after CT treatment.
Therefore, these results demonstrated that CT stimulated the biosynthesis of intestinal ALP in intestinal epithelial cells in rats.
