Experimental renal papillary necrosis in the rat: the selective vulnerability of medullary structures to injury.

Acute renal papillary necrosis was produced in rats by the administration of ethyleneimine. Low doses resulted in necrosis of interstitial cells, thin limbs of the loops of Henle and vasa recta, while collecting ducts were spared (subtotal renal papillary necrosis). High doses resulted in necrosis of all elements of the papilla (total renal papillary necrosis). Athough the ranges of the doses that produced these two patterns of necrosis overlapped, it is clear that there is a dose dependent selective vulnerability or renal medullary structures to injury by the toxic agent studied.