Chronic pyelonephritis. An electron microscopic study in nonhuman primates.

The rhesus monkey (Macaca mulatta) proved to be a successful model for the ultrastructural study of ascending nonobstructive pyelonephritis. The most severe kidney damage occurred where the inflammatory response was greatest, and these areas overlaid a dilated or clubbed calyx. The most prominent ultrastructural changes were in the renal tubular cells that showed swollen mitochondria with ruptured inner membranes, dilated endoplasmic reticulum, and flocculent and irregular basal laminae. No recognizable bacterial structures were seen.