Studies on the inhibition of intestinal absorption of radioactive strontium. V. The effect of administration of calcium alginate.

A method of selective suppression of absorption of radioactive strontium from ingested food material is described which allows calcium to be available to the body. In the present study the effects of administering calcium alginate were determined. Studies on the relative binding of Ca and Sr by calcium alginate in vivo are also important to the investigation of calcium-strontium exchange.Samples of calcium alginate were obtained commercially or prepared from sodium salts and the binding properties with Ca(45) and Sr(89) were tested in vivo. There was a free exchange of radioactive calcium as well as of strontium with bound inactive calcium. The amount of Ca(45) retained in the gut by calcium alginate is proportionally less than Sr(89), so that the ratio Sr(89)/Ca(45) in the bone is consistently and significantly lower in treated rats. Calcium alginate acts differently from other calcium salts, although in a manner similar to sodium alginate.