Effects of parathyroid extract. II: changes preceding renal calcification

Abstract

Parathyroid extract, a total of 860 units, has been administered to rats in small, progressively increasing doses over a period of 12 days. The effects on serum protein, total glycoprotein, glycoprotein/protein ratio, calcium, individual protein and glycoprotein fractions, and renal calcification have been presented. Kidney sections from each rat were studied by histochemical techniques for calcification, neutral polysaccharide, and acid mucopolysaccharide. The serum total glycoprotein, glycoprotein/protein ratio, and calcium were found to be elevated. The serum albumin was decreased, whereas the globulin fractions were essentially unchanged. The globulin glycoprotein hexose, mostly α₁-globulin, was increased; albumin glycoprotein hexose showed a somewhat less consistent increase. A "precalcification" periodic acid-Schiff-staining intraluminal material was demonstrated in the kidney after parathyroid extract treatment for 4 days. This was followed approximately 2 days later by Alcian blue-staining material and calcification demonstrable by hematoxylin and eosin and by Kóssa staining techniques. This has been interpreted as suggesting a glycoprotein-containing lesion which precedes calcification.