Masugi's nephritis from the age aspect

Abstract

Masugi's nephritis was induced in Wistar rats aged 3 months and 6 and 3 weeks. Identity of the intensity and duration of fixation of nephrotoxic antibodies in the renal glomeruli was established irrespective of the animals' age, and fixation was accompanied by a lowering of the serum complement level. The disease followed the severest course in the rats aged 6 weeks. The proliferative-membranous glomerulitis which they developed after 48 h increased in severity and was accompanied by the development of autoimmune processes. The mortality among the experimental rats was 35%. The disease followed the mildest course in the rats aged 3 weeks. In these animals, unlike the other groups, the morphological changes in the kidneys were not accompanied by increased proteinuria and they had no tendency to progress. In the course of the disease a steady increase in the complement level was observed. Toward the end of the experiment all the animals were still alive. The difference in the course of the disease in the young rats was evidently connected with differences in their immunological reactivity: an extremely low initial serum complement level, high initial acid phosphatase activity of the blood neutrophils, and the appearance of foci of infiltrating lymphocytes and plasma cells in the interstices of the renal cortex.