Glomerular lesions in 8A4 mice kidneys.

(A and B) Light microscopy showing the proliferative and exudative changes (A, original magnification ×200, light green trichromic staining) and the voluminous depositions of material predominantly in mesangial and subendothelial areas (B, original magnification ×1000, semi-thin section, toluidine blue staining). (C) Immunofluorescence microscopy with antimouse Ig conjugate (original magnification ×200) showed intense staining of deposits strictly limited to glomeruli without any staining of peritubular capillary lumen. (D and E) Electron microscopy showed osmiophilic deposits in mesangial and subendothelial spaces (wire-loop lesion) with few subendothelial deposits. The glomerular capillary lumens were free of deposits (D, original magnification ×5000). Note the highly organized crystalline glomerular deposits formed by densely packed microtubules (external diameter = 12 nm) in transversal section and parallel arrays in longitudinal section with a 12-nm striation periodicity (E, original magnification ×60 000).