Progressive renal lesions induced by administration of monoclonal antibody 1‐22‐3 to unilaterally nephrectomized rats
A new animal model of progressive glomerulosclerosis was developed by administering a single i.v., injection of MoAb 1–22–3 to unilaterally nephrectomized rats. Renal morphological analysis revealed that glomerular lesions characterized by mesangial cell proliferation and mesangial matrix expansion were induced in about 95% of the glomeruli. Approximately 20% of the glomeruli of the unilaterally nephrectomized rats showed sclerosis or segmental sclerosis by week 6 after MoAb injection and crescent formation was observed in some glomeruli (ca 4%). Cellular infiltration was also noted in some parts of the interstitium. Increased expression of transforming growth factor–beta (TGF‐β) was observed in the unilaterally nephrectomized rats treated with MoAb 1‐22‐3, but we could not demonstrate pathological involvement of platelet‐derived growth factor (PDGF). even though early‐stage mesangial cell proliferation was observed. The mechanism of mesangial cell proliferation in this model remains to be elucidated. The relatively short period of time needed to induce the sclerotic changes is considered to be a great advantage of this model for clarifying the mechanisms involved in the chronic progression of mesangial proliferative glomerulonephritis.