[Absence of litholytic effects of zinc sulfate and copper sulfate in experimental lithiasis in rats]

Seventy two male Wistar-strain rats were fed lithogenic diet with ethylene-glycol within three weeks. At the end of this treatment, six rats were killed in order to determine the oxalate and calcium concentrations in renal tissue. Remained rats was randomly divided in four series, each series consisting of three groups. In first series (T), the animals were treated with distilled water; in the second (D1Zn), the animals were treated intramuscularly with the zinc at the rate of 24 micrograms per 100 grams of body weight and per day; in the third (D2Zn), 240 micrograms of zinc were administrated to animals and in the last series (D2Cu), the animals were treated at the same dose as the previous series, but with the copper. The groups which making up each series were killed successively at the 5th, 10th and 15th day after ending treatment with ethyleneglycol in order to determine urinary pH, percentage of water in renal tissue, uremia and concentrations of oxalate and calcium in renal tissue. Then, the comparisons of means were carried out, at each time, between different treated groups and reference group which was treated with distilled water. Litholytic effect was found in all series, including that which had been treated with distilled water. However, compared to reference animals, no acceleration of litholytic process was induced by zinc or copper. The high doses used in these experimentations proved therefore that calcium oxalate calculi were insoluble by zinc and copper.