The Effect of Calcium Infusions on Renal Handling of Amino Acids in Hypophosphatemic Vitamin D Resistant Rickets

Abstract

Amino acid clearances were studied in four patients with hypophosphatemic vitamin D resistant rickets. T,e clearances of the single amino acids in the patients did not differ from that of control individuals for all amino acids tested. The reabsorption of amino acids and phosphate was further investigated with the use of calcium infusions. Under these conditions there was a significant decrease in the filtered fraction of phosphate and amino acid excreted in the vitamin D resistant group suggesting a depression of parathyroid hormone secretion. It seems likely, as demonstrated in the vitamin D resistant group, that in this disorder the renal tubule is particularly sensitive to changes in parathyroid hormone secretion in respect to amino acid reabsorption.