Effect of colchicine on intestinal alkaline phosphatase activity during linoleic acid absorption in rats

The purpose of this study is to examine whether intestinal alkaline phosphatase (IAP) plays a role in transporting lipoproteins to lymphatics during fat absorption. In control rats, the increased activity of IAP in intestinal lymph was observed parallel with the amount of absorbed linoleic acid. In colchicine-treated rats, lymphatic absorption of intraduodenally administered linoleic acid was decreased and administered lipid was transported slowly to lymphatics, mostly in the form of free fatty acid. However, the equal or slightly larger amount of output of IAP to lymphatics was observed in spite of the decrease in lipid absorption in colchicine-treated rats. Histochemically, prolonged activity of IAP in stroma and submucosal lymphatics was found in colchicine-treated rats fed with fat. These results suggest that microtubules are not involved in IAP transport into lymphatics, and these data do not necessarily rule out that IAP plays a role in lipoprotein transport.