[The activity of several enzymes of the mucous membrane of the intestine during thiamine absorption].

With increasing amounts of thiamine introduced into the intestines the extent of its absorption by the intestinal mucosa is shown to decline. The activity of thiamine-pyrophosphatase (KF 3.6.1.6) in the intestinal mucosa rises with absorption of physiological and large quantities of thiamine, whereas Na+-K+-activated ATPase (Kf 3.6.1.3) becomes activated only with absorption of physiological doses of vitamin B1. The participation of these enzymes in the regulation of the thiamine absorption in the intestines is suggested.