title: Tubulointerstitial lesions in young Zucker rats.
abstract: Zucker (Z) rats spontaneously develop proteinuria and focal glomerulosclerosis (FGS), but little is known about tubulointerstitial (TI) changes in the early stages of their disease. Thirteen male Z rats (9 obese, 4 lean) were examined at 75 (n = 6) and 120 (n = 7) days of age. Twenty-four-hour urinary protein excretion (UPr), percent of glomeruli with FGS, proportion of cortex and outer stripe occupied by vimentin (V)-positive (+) tubules (a marker of tubular damage) and the number of OX4+ (Ia+), OX42+(monocyte/macrophage), OX19+(pan T cell), OX8+(T cytotoxic cell), and OX22+(B cell) cells in both normal areas and around V+ tubules were assessed at each age. Mean UPr was 34.2 +/- 18.5 mg/day at 75 days and 183.6 +/- 129.9 mg/day at 120 days. FGS was only observed in 1% to 3% of glomeruli in five 120-day-old obese rats. All rats showed varying degrees of focal TI injury histologically. V+ tubules were observed in 12 rats, and the proportion of cortex and outer stripe occupied by V+ tubules varied from 0.1% to 7.7%. The extent of TI damage was greater at 120 days (3.7% +/- 2.9%) than at 75 days (0.5% +/- 0.5%). There was a 2- to 12-fold increase in the number of OX4+, OX42+, OX19+, and OX8+ cells in areas around V+ tubules, with OX4+ and OX42+ cells predominating.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Pathology and Laboratory Medicine, St Paul's Hospital, Vancouver, BC, Canada.
authors.forename: A B
authors.initials: AB
authors.lastname: Magil
mesh_terms: D000375:Aging; D000818:Animals; D001402:B-Lymphocytes / Q000473:pathology; D005923:Glomerulosclerosis, Focal Segmental / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism / Q000473:pathology*; D008297:Male; D009000:Monocytes / Q000473:pathology; D009395:Nephritis, Interstitial / Q000378:metabolism / Q000473:pathology*; D011507:Proteinuria / Q000378:metabolism / Q000473:pathology; D051381:Rats; D011924:Rats, Zucker; D013601:T-Lymphocytes / Q000473:pathology