[Changes in the activity of alkaline phosphatase and the level of thiamine diphosphatase in simulations of B1 avitaminosis].

Alimentary B1 avitaminosis was attended by a declining activity of alkaline phosphatase in the brain and spleen of rats. A single administration of oxythiamine to rats in a dose of 400 mg/kg produced during the first hours an increased activity of alkaline phosphatase in the liver, brain and, to a lesser extent, in a number of other organs and reduced the thiamine-diphosphate content in the liver, brain and other tissues. The thiamin-diphosphate level in the brain returned back to normal in 12 hours, and in other tissues-towards the 3--5th day. In 24 hours after introduction of oxythiamine the activity of alkaline phosphatase was up in the liver alone, while in the brain the activity of the enzyme decreased. Thiamine, used in a dose of 400 mg/kg, exerted on the activity of alkaline phosphatase in a number of tissues an action similar to that of oxythiamine. It is suggested that the activation of alkaline phosphatase 3--12 hours following adminstration of a large dose of thiamine or oxythiamine is of a non-specific nature. Subcutaneous introduction of a commercial alkaline phosphatase preparation to rats brought down the thiamine-diphosphate level in all of the tissues under investigation. The presumed mechanisms accounting for the fall of thiamine-diphosphate and the possible part played in this process by alkaline phosphatase are discussed.