Abstract
In order to investigate the effect of antigenic charge on the glomerular localization of immune complexes (IC), we used the system of chronic serum sickness nephritis in rabbits. Chemically modified cationic BSA was used as an antigen. Rabbits were immunizedd with 4 mg of cationic BSA containing Freund's complete adjuvantd After 2 weeks, 500μg of cationic BSA, were daily injected intravenously for 6 weeks and l week later, renal biopsy and bleeding were performed (1st biopsy). After 1 week, furthermore, these rabbits were injected daily 5 mg of cationic BSA for 1 week and 1 week later, renal biopsy and bleeding were performed (2nd biopsy) Renal specimen at 1st biopsy showed no significant finding of glomerular capillary walls, but at 2nd biopsy it revealed typical membranous glomerulonephritis. The prowperties of antibody to cationic BSA showed low precipitating and low avidity at bothh biopsies. Antigen to antibody ratio was in antibody excess state at 1st biopsy, but in antigen excess state at 2nd biopsy. From the above results, we speculated that: 1) Chemically modified cationization alters the immunogenicity of BSA, thereby producing low precipitating and low avidity antibody even in prolonged immunization. 2) Membranous glomerulonephritis induced in this system may result from small sized circulating IC depositions in antigen excess state.
