Depletion of peritoneal B cells reduces albuminuria in mice with adriamycin nephropathy. Peritoneal cells are depleted with hypotonic shock, starting 2 weeks before the induction of adriamycin nephropathy. Urine albumin/creatinine levels are measured. (A) Peritoneal depletion of B cells significantly attenuates the level of albuminuria 1 week and 4 weeks after injection of the adriamycin. (B) Representative glomeruli from mice in each group are shown. The kidneys are stained with periodic acid–Schiff, and glomeruli are indicated with arrowheads. (C) The percentage of each glomerulus occupied by matrix is determined as an index of glomerulosclerosis. Peritoneal cell depletion reduces the degree of glomerulosclerosis compared with PBS-treated mice with adriamycin nephropathy. (D) Staining of kidneys for collagen IV demonstrates that injection of mice with adriamycin causes an increase in glomerular collagen IV deposition, and this is not significantly affected by depletion of peritoneal B cells. Thirty glomeruli per section are visualized, and the average for each mouse is determined. Representative glomeruli from mice in each group are shown. Original magnification, ×400. Scale bar, 100 μM.