Zinc metabolism in aminonucleoside-induced nephrosis

Nephrosis was induced in Sprague-Dawley rats in two separate studies by injections of aminonucleoside with sacrifice of animals on days 20 and 54, respectively. Experimental animals in both studies showed the typical findings of nephrosis, i.e., hypoalbuminemia, hypercholesterolemia, and proteinuria. Biochemical findings included hypozincemia and hyperzincuria. A significant correlation between hypozincemia and hypoalbuminemia was noted in the short-term study. Proteinuria occurred on the 10th day in the short-term study and the 15th day in the long-term study and increased quantitatively over the remaining days. The hyperzincuria and proteinuria correlated significantly in the long-term study. Measurements of tissue zinc revealed no change in testes and kidney in the short-term study. Kidney and muscle zinc were increased, testicular zinc was unchanged and femur zinc was decreased in the long-term study. Our conclusions are that in the aminonucleoside induced nephrosis of the rat: 1) hypozincemia occurs probably as a result of hypoalbuminemia, 2) the hyperzincuria is likely due to proteinuria and 3) zinc deficiency is not observed in nephrotic rats who receive ample zinc in their diet and who are observed up to 6 weeks.