Modulation of glomerular structure after BMT. a: Glomerular hypertrophy and expansion of the extracellular matrix, tubular atrophy, thickened tubular basement membranes, and interstitial inflammatory cell infiltration were present in 22-month-old naïve mice (22 months). PAS stain. b: Glomerular and tubulointerstitial lesions were prominent in 18-month-old recipients of BMT from 18-month-old mice (18 months → 18 months, age at BMT = 18 months; age at sacrifice = 22 months), changes similar to that of 22-month-old naïve mice. Sacrif, sacrifice; m, month. c: Glomerular hypertrophy and extracellular matrix expansion were less evident, and tubulointerstitial lesions were less severe, in 18-month-old recipients of BMT from 4-month-old mice (4 months → 18 months). d: Glomerular hypertrophy was significantly decreased in 4 months → 18 months compared to 22 months or 18 months → 18 months (*P < 0.05). e: Mesangial area was decreased in 4 months → 18 months compared with the 22 months or 18 months → 18 months (*P < 0.05). The mesangial areas of 22 months and 18 months →18 months were similar. Original magnification, ×400 (a–c).