[Effect of fluoride and insulin on cation-dependent ATPase activity of the enterocytes during threonine absorption]

Absorption of threonine was accompanied by a distinct increase in total activity of Mg2+- and Na+, K+-ATPases in rat small intestine. Sodium fluoride inhibited completely the Na+, K+-ATPase activity. After administration of insulin, activity of Na+, K+-ATPase was increased 2-fold without loading with threonine, and it was increased 3.3-fold in the amino acid loading. Sodium fluoride activated Mg2+-ATPase, insulin did not affect the enzyme activity but the hormone decreased partially the inhibitory effect of sodium fluoride on Na+, K+-ATPase.