COPPER AND ZINC-METABOLISM IN AMINONUCLEOSIDE-INDUCED NEPHROTIC SYNDROME

Copper (Cu) and zinc (Zn) were measured in urine, serum and tissues fr om rats with nephrotic syndrome (NS) induced with a single subcutaneou s dose of puromycin aminonucleoside (PAN; 15 mg/100 g BW). Control ani mals were pair-fed. Urine was collected daily, and the rats were sacri ficed on day 10. PAN-nephrotic rats had proteinuria (days 3-10), high urinary Cu (days 1, 2, 4-10) and Zn (days 3-10) excretion. On day 10, nephrotic rats had: (a) albuminuria, hypoalbuminemia, hypoproteinemia, high urine and low serum levels of ceruloplasmin; (b) low Cu and Zn s erum levels; (c) high clearance and fractional excretion of Cu and Zn, and (d) low kidney and liver Cu content and essentially normal tissue Zn levels. The alterations in Cu metabolism were more intense than th ose in Zn metabolism. Urine Cu and Zn showed a positive correlation Ce ruloplasmin with urine total protein on days 3-10 which suggests that high urinary excretion of Cu and Zn may be due to the excretion of its carrier proteins. In conclusion, these rats did not show a typical Zn deficiency but a clear decrease in Cu in the liver and kidney.