Inhibition of Experimental Nephrocalcinosis by Hypophysectomy.∗

Summary 1) Experiments on rats indicate that oral administration of excess sodium phosphate causes intense calcification in the “zona intermedia” of the kidney in intact but not in hypophysectomized rats. 2) The “gran-uloma-pouch” technic permits the subcutaneous administration of as much as 10 ml of 5% NaH2PO4 per rat daily. (Normally, this amount could not be given subcutaneously because of its topical necrotizing effect.) When so administered, the phosphate solution causes a generalized nephrocalcinosis throughout the kidney and this is also virtually abolished by hypophysectomy. Apparently, hypophyseal hormones play an important conditioning role in the pathogenesis of this kind of nephrocalcinosis. 3) Repeated injections of hypertonic phosphate solutions, into subcutaneous gran-uloma-pouches, cause the formation of numerous hyalin casts and protein-precipitates in the kidney and this change was likewise totally abolished by hypophysectomy. When thus administered, phosphate solutions can also induce a pronounced and highly selective atrophy of the entire outer renal cortex, but this change is essentially of the same severity in the presence and in the absence of the hypophysis.