Carbohydrates and Gastrointestinal Absorption of Radiostrontium and Radiocalcium in the Rat.

Abstract

Fasting young male rats were given by gavage a solution containing Ca45 and/or Sr85, 0.04 mmoles CaCl2 and 0.42 mmoles of the test substance. The femur content of the radionuclides at 24 hours after dosing was used as an index of absorption. By this technique, it was observed that cellobiose, sorbose, xylose, ribose, lactose, raf-finose, melibiose, glucosamine, mannitol and sorbitol significantly enhanced alkaline earth absorption whereas glucose, galactose, fructose and sucrose had little or no effect. The ability of the effective carbohydrates to increase Ca and Sr absorption appeared to be positively correlated with a prolonged residence time in the gut or absorption of carbohydrate by a passive mechanism. In a balance-type study with rats using Sr85, the enhanced retention of radionuclide could be accounted for by an increased intestinal absorption rather than a direct effect of lactose on skeletal ossification.