[Effect of sorbitol on the activity of alkaline phosphatases isolated from different areas of rat small intestine].

To elucidate by which way sorbitol (S) increases Ca absorption, the action of (S) on the alkaline phosphatases (A.P.) isolated from duodenum, jejunum and ileum of the young rat is studied. At pH = 9,8 A. P activation by (S) is the most pronounced with ileal A.P. At each studied pH (greater than or equal to 8) the ability of A. P to phosphorylate (S) is observed constantly. A diffusional system transfer of Ca is proposed involving the intervention of a A. P under the inhibiting control of phosphates. This inhibition would be suppressed by the A. P transphosphorylating action toward (S).