The effect of phenylbutazone upon dihydrotachysterol overdosage in the rat.

Experiments on albino rats showed that short-term overdosage with dihydrotachysterol, in amounts causing only traces of soft-tissue calcification, induced a very pronounced calcium deposition in the heart, aorta, and kidney when the animals were simultaneously treated with phenylbutazone. Special attention is called to the fact that, under these experimental conditions, it is possible to obtain consistently a massive calcium deposition in the stroma of the renal papilla similar to that seen in "Randall's plaques" during the development of urolithiasis in man.