Scanning electron microscopy of experimentally induced pyelonephritis in the rat.

Scanning electron microscopy was used to observe epithelial and inflammatory changes in kidneys of rats during Corynebacterium renale-induced experimental ascending pyelonephritis. Bacteria were not observed adhering to pelvic epithelium, although there was evidence of cell sloughing. Bacteria was observed in the interstitium of the renal medulla. Bacteria, when present in the tubular lumen, were associated with discontinuities in cell membranes. Phagocytic cells appeared in the interstitium and phagocytosis was evident in the renal medulla.