Urolithiasis in the Rat. V. In vivo Dissolution of Calculi. ∗

Abstract

Summary

Uroliths can be formed readily in the weanling NMRI-D rat by feeding a diet containing 15% casein and 4% HMW salt mixture. The calculi are found predominantly in the bladder, sometimes in the bladder and renal pelvis, but rarely in the kidney alone. Calculi formed by the above dietary means can be dissolved in vivo by changing the diet to include more protein and less mineral. It appears that the process of dissolution takes place in a sequence, involving first a demineralization and then dissolution of the matrix. Rats fed diets in the order of calculogenic—protective—calculogenic were found to have an unusually high occurrence of renal calculi without stones being found in the bladder. This may be related to the age of the animals.