[Effects of alkaline phosphatase inhibitors on intestinal transfer of calcium]

Adults rats receive by gavage 10 mM CaCl2 [+45Ca] solution containing or not 100 mM glucid, 10-100 mM EDTA or these both compounds. Calcium transfer is determined by the evaluation of [45Ca] in intestine and feces as well as in plasma and femur. Basic Ca++ transfer which corresponds to the CaCl2 solution was doubled in the presence of glucids. EDTA addition abolishes completely the glucid effect, exercising any influence on basic CA++ transfer. Injected into ligaturated ileal loop, the glucid gives the same effect. But the addition of phosphate not only removed glucid action but also inhibits the basic Ca++ transfer. The glucids, known acceptors of phosphate, increase Ca transfer. EDTA and phosphate, alkaline phosphatase inhibitors, exhibit an opposite effect. Phlorizin, as it was seen previously, acts exactly as EDTA. All these facts question: the simultaneous transfer of Ca and glucid, the possibility of a glucid phosphorylation, the part in these events of alkaline phosphatase, phosphorylating, phosphatasic and phosphorylable microvillar protein.