Renal Excretion of Calcium by the Dog

Abstract

Utilizing flame photometry as an analytical tool and serum ultrafiltration to estimate the glomerular filterable Ca, some aspects of the renal excretion of Ca by the dog were investigated. Ca reabsorption by the renal tubules is an active process normally exceeding 99% of that filtered. The small but constant amounts of Ca excreted are thought to be an un-ionized complex. Ca excretion is increased following the intravenous injection of sodium phosphate or tetra sodium versene. The increased serum inorganic phosphate concentration following intravenous Ca administration was accompanied by a compensating fall in red blood cell organic phosphate esters.