Reversible changes in small infarcts of the rabbit kidney.

Infarcts of the rabbit kidney were experimentally induced in 22 animals by selective left renal arteriography using the genuine foreign bodies present in the contrast media and catheters as damaging agents. Three days later the infarcts were macroscopically located and measured at laparotomy. Three weeks later the infarcts were macroscopically and microscopically investigated. Small infarcts (below 5 mm diameter) now were rendered grossly invisible, and no fibrous scarring of the infarcted area was present. Histologically, the changes varied from slight atrophy to total lack of microscopical parenchymal changes. Greater infarcts (above 5 mm in diameter) showed traditional cicatricial changes, the degree of scarring being dependent of the initial size of the infarct. Thus the small infarcts were found to be able to regenerate and revascularize.