Feline glomeruli: morphologic comparisons in normal, autolytic, and diseased kidneys.

Twelve cats were used to study autolytic changes in glomerular morphology and compare these with lesions of naturally occurring feline renal disease. The 12 cats had normal clinical, urinary, and blood features. One kidney (0-hour control) was excised immediately after a given cat was euthanatized, and portions of it were prepared for light and electron microscopy. The opposite kidney (autolytic) remained in situ for selected postmortem intervals, up to 24 hours, at which time it was similarly processed. Renal tissues from 4 additional cats (3 with proteinuria and 1 with diabetes mellitus) were processed and examined for comparison. Zero-hour control kidneys had the following mean quantitations: renal weight was 9.9 g; glomerular diameter, 83 mum; number of cells per glomerulus in 1-mum section was 63; and diameter of cell nuclei was 6.3 mum for mesangial, 6.7 mum for visceral epithelial, and 6.4 mum for endothelial. In comparison with 0-hour control kidneys, autolytic kidneys had increased weight and glomerular diameter, but the diameter of cell nuclei decreased. Basement membrane thickness and glomerular cell numbers did not differ between 0-hour control and autolytic kidneys. Kidneys from 4 diseased cats had increased glomerular diameter and glomerular basement membrane changes characterized by hyalin thickening and dense deposits. These changes are compatible with a lesion diagnosis of membranous glomerulonephritis.