[Antilithogenic and litholytic action of vitamin A vis-a-vis experimental calculi in rats]

Oxalate lithiasis was induced in control rats and rats previously given a vitamin A supplement for one week at the dose for 200 UI/d/kg body weight. Oxalate and calcium deposits in renal tissue measured 24 hours after the induction of lithiasis were found to be significantly lower in the vitamin A supplemented rats (p < 0.001 and p < 0.01) respectively). Renal function in these animals was also improved as compared with controls (p < 0.05). However, when vitamin A supplements were given for the same period and at the same dose, but after the induction of oxalate lithiasis, no difference regarding oxalate and calcium deposits was found between the two groups of animals. The same applied to renal function, which showed no improvement in the supplemented animals as compared with controls. These results suggest that vitamin A supplements have an inhibitory effect on lithogenesis but probably no litholytic action as such. The effect of vitamin A is probably related to its action on tubular cellular repair or an inhibitory effect on necrosis of these cells.