Effect of Time of Injection on Removal of CA-45 and SR-85 by Peritoneal Lavage.

Abstract

By use of the technique of peritoneal lavage, removal of Sr85 and Ca45 from bone was studied relative to time of injection of the radioactivity. Earlier studies showed that neither parathyroidectomy nor addition of citrate to lavage rinse had any effect on removal of radiocalcium injected 24 to 48 hours prior to start of lavage. Similar results with radiostrontium substantiated the earlier studies. In addition, experiments in which the radioactivity, both calcium and strontium, were allowed to remain in the animal 2 to 3 weeks before lavage procedures were done. In these experiments, parathyroidectomy reduced the amount of radioactivity removed, while addition of citrate to the rinse increased it. Under these situations, therefore, changes in rate of removal of radioactivity paralleled changes in removal of total calcium. These experiments are taken as additional evidence that calcium is removed from bone by 2 processes, one possibly an equilibration phenomenon between fluid media of body and those portions of bone with which it is in closest contact. The second is removal of Ca from deeper areas of bone, under the influence of hormone of the parathyroids.