Serum and urinary ceruloplasmin in experimental nephrotic syndrome

The levels of ceruloplasmin (Cp) and total protein were measured in serum and urine from rats with experimental nephrotic syndrome (NS) for 20 days after a single injection of puromycin aminonucleoside (PAN). Control values for Cp in serum and urine were: 0.23 +/- 0.01 mg/ml and 0.063 mg/day, and those for total protein were: 7.1 +/- 0.14 g/dl and 2.1 +/- 0.6 mg/day, respectively. It was found that: a) serum Cp decreased on day 6, remained low until day 10 (0.07 +/- 0.01 to 0.08 +/- 0.01 mg/ml), and returned to control levels on day 12; b) total serum protein decreased on day 4, reached the lowest value on day 6 (3.3 +/- 0.3 g/dl) and returned to control levels on day 16; c) Cp in urine increased on day 6, reached a peak value on day 8 (0.62 +/- 0.07 mg/day), then decreased but remained high on day 20; and d) total protein in urine increased on day 5, reached a peak value on day 10 (692 +/- 59 mg/day) and returned to control values on day 20. There was a close association between the levels of Cp and total protein in serum and urine. The decrease of circulating Cp indicates that a typical acute phase response does not occur in the PAN-nephrotic rats. The loss of Cp in the urine of the nephrotic rats may contribute to the decrease in the serum levels of this protein.