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D W EDWARD

Publications and source records attributed to D W EDWARD.

10 recordsLinked to original sources

STUDIES ON INHIBITION OF INTESTINAL ABSORPTION OF RADIOACTIVE STRONTIUM. II. EFFECTS OF ADMINISTRATION OF SODIUM ALGINATE BY OROGASTRIC INTUBATION AND FEEDING.

A method is reported that enables selective suppression of absorption of radioactive strontium from ingested food material, permitting calcium to remain available to the body. Studies were carried out by measuring blood levels and bone uptake of Sr(89) and Ca(45) at different time intervals after orogastric intubation of rats. The addition of sodium alginate, derived from brown marine algae, to the radioactive isotopes increased the overall physiological discrimination against strontium by amounts up to 60% after 24 hours. This discrimination was further increased by feeding sodium alginate mixed with standard diet in the proportions of 20:80 and 30:70. The observed ratio was reduced by administration of sodium alginate from 0.25 to 0.09.Determination of the limiting dosage in rats is restricted to the amounts which rats will consume. In the event of an inadvertent release of radioactive strontium, human subjects probably could increase their intake of alginate at will, permitting a greater effectiveness of sodium alginate than could be obtained in experimental animals.

Absorption↗

STUDIES ON INHIBITION OF INTESTINAL ABSORPTION OF RADIOACTIVE STRONTIUM. I. PREVENTION OF ABSORPTION FROM LIGATED INTESTINAL SEGMENTS.

A method is reported which permits selective suppression of absorption of radioactive strontium from ingested food material, permitting the calcium to be available to the body. Studies were carried out in vivo by injection of Sr(89) and Ca(45) in the presence of inert carrier into ligated intestinal segments in rats, and the amount of absorption was measured by standard monitoring techniques. The pattern of absorption of both ions is very similar but the rate of absorption is different. It was found that the polyelectrolyte, sodium alginate, obtained from brown algae (Phaeophyceae), injected simultaneously with radiostrontium effectively reduces the absortion of Sr(89) from all segments of the intestine by as much as 50-80% of the control values. No significant reduction in absorption of Ca(45) was observed in equivalent concentrations. The reduction in blood levels of Sr(89) and in bone uptake corresponded to the absorption pattern. The difference in the effect on strontium and calcium absorption may be due to differences in the binding capacity of sodium alginate from the two metal ions under the conditions present in vivo.

Absorption↗