Effect of parathyroid extract and phosphate salts on renal calcium and phosphate excretion after parathyroidectomy.

Abstract

SummaryChanges in renal phosphate and calcium excretion in the 24 hours following parathyroidectomy in the rat have been studied. Parathyroidectomy alters renal control of phosphate excretion so that little phosphate is excreted until serum phosphate is increased to about 13 mg %. Excretion increases suddenly about 16 hours postoperatively in untreated rats but occurs sooner if phosphate ions are injected to hasten the rise in serum phosphate. Parathyroid extract hastens return toward normal excretion rates by altering the renal mechanism for excretion toward the normal state. Calcium excretion increases considerably at parathyroidectomy but declines as the serum level falls and returns to a normal rate at about the same time as does phosphate excretion in the untreated animal (16 hr). This also appears to be due to changes in the renal excretory mechanism. By its effect on this mechanism, parathyroid extract hastens the return of calcium excretion to within normal limits, this occurring at higher serum c...