[New correlation between absorption of calcium and activity of intestinal alkaline phosphatases]

From an homogeneous breeding one can occasionnally select a rat (rat +) showing an exceptionally high calcium absorption. For such a rat, high calcium absorption is accompained by a similar high alkaline phosphatase activity in the ileum. This fact was shown in six different assays. For rat +, this enzymatic excitation seems specific for intestinal phosphatase. Other characteristic enzymes of brush border such as maltase, invertase and leucylaminopeptidase do not vary much. Only slight modifications of phosphatase activity were observed in other organs or tissues: plasma, kidney, bone. The variations for liver are more important but unsignificant. The high calcium absorption is related to alkaline phosphatase. It is observed atdifferent steps of the preperation and can be increased by sorbitol, this last property being characteristic of the enzyme. The aptitude of a rat + for high calcium absorption is only momentany. When it goes back to usual calcium utilization, intestinal mucosa shows a normal phosphatasic activity.