Indomethacin and lysine acetylsalicylate in rats with autologous nephrotoxic serum nephritis. Biochemical and morphological studies.

The effects of indomethacin and lysine acetylsalicylate (L-ASA) were compared in rats in which autologous nephrotoxic serum nephritis had been induced. The aim of this study was to offer support to the hypothesis that indomethacin might reduce proteinuria through increased synthesis of glomerular basement membrane by the podocytes. Both drugs were injected intraperitoneally at the dosage of 4 mg/kg body weight daily during a 6-day period into 40 rats rendered nephritic by rabbit nephrotoxic serum injection. Rats treated with indomethacin showed a marked decrease of proteinuria (tested by the 3% sulfosalicylic aicd method) and a clear ultrastructural picture of hyperplasia and hypertrophy of podocytes. Rats given L-ASA showed only a slight correction of proteinuria and less specific ultrastructural modification. These observations suggest that indomethacin decreases proteinuria in nephritic rats not only through its anti-inflammatory activity, but possible also by a peculiar mechanism, namely an increase in podocytic basement membrane synthesis.