Kazunari Iidaka

Autosomal Recessive Polycystic Kidney in Rats

We evaluated the characteristics of renal lesions in rat autosomal recessive polycystic kidney (ARPK). In rat ARPK, small cysts appeared primarily in the medulla 2 months after birth and gradually extended to the cortex, forming large cysts involving the entire layer after 8 months. By immunofluorescence microscopy, type IV collagen was more strongly stained in the epithelial basement membrane of the rat ARPK than in the normal rat tubular basement membrane (TBM). Electron microscopy demonstrated a marked thickening, slight splitting and lamination of the TBM in the ARPK. As peroxidase-labeled lectins, dolichos biflorus very strongly stained the cyst epithelium whereas lens culinaris did not. These findings indicate that cysts in rat ARPK originate in the collecting duct.

Glomerulonephritis with predominant paramesangial IgG deposition.

The new clinicopathological entity, Immunoglobin G (IgG)‐associated mesangial prollferative glomerulonephritls (GN), has been reported recently, but serial renal biopsies were not performed In the cases reported. The findings of three serial renal biopsies In a pediatrlc case with IgG‐associated GN and paramesangial deposits are reported. Microscopic hematuria was found Incidentally at the age of 8 years and the hematuria often worsened transiently during periods of upper respiratory infections. The patient was treated mainly with dipyrldamole. The third biopsy showed that both para‐mesangial hemispherical deposits and predominant mesan‐gial IgG deposits had increased, while mesangial cell proliferation had markedly decreased. These serial biopsy findings suggest that IgG‐associated GN with microscopic hematuria and slight proteinuria may be characterized by a relatively benign histoiogical and clinical course, as described in recent reports.

Cystic Basement Membrane with Increased Negative Charge in Rat Autosomal Recessive Polycystic Kidney

Cystic Basement Membrane with Increased Negative Charge in Rat Autosomal Recessive Polycystic Kidney Z. Zenshiro Inage Y. Yumio Kikkawa M. Motoyuki Minato M. Misao Owada T. Teruo Kitagawa K. Kyoko Ohno K. Kyoji Kondo Y. Yoshihiko Ueda K. Kazunari Iidaka Department of Pediatrics, Nihon University, School of Medicine, Tokyo; Laboratory of Experimental Animals, Yagi Memorial Park, Gifu; Second Department of Pathology, Dokkyo University, School of Medicine Tochigi, Japan