Non-epithelial basement membrane thickening in the urinary tract associated with phenacetin abuse

Abstract

In four cases of capillarosclerosis in the urinary tract associated with analgesic (phenacetin) abuse, the basement membrane (BM) thickening was not confined to the subepithelial capillaries, but was also found around the smooth muscle cells in the luminal part of the tunica muscularis. Electron microscopy confirmed that the changes in the BM around the smooth muscle cells were similar to those seen around capillaries. This non-vascular affection of BM in the urinary tract in patients with phenacetin abuse has not been reported previously. Thus, capillarosclerosis appears to be only part of a BM disorder, that clearly diminishes in intensity with increasing distance from the lumen. It is therefore suggested that the changes are caused by some agent (possibly a metabolite) in the urine diffusing from the lumen into the wall of the urinary tract.

Enzyme Histochemical Changes in an Acutely Induced Renal Papillary Necrosis

“…The thickening of the ATPase stained areas, to the point where the lumen of the vessel was occluded, suggests that a capillary sclerosis had occurred. A microangiopathy, with a progressive narrowing ofthe capillaries due to basement membrane thickening and the deposit oflipid material, has been described in humans with RPN (12,20,21,25). These changes are thought to be pathognomonic in human analgesic abusers, but have not been reported previously in animal models of RPN (14) and, therefore, warrant further investigation.…”

“…2-Bromoethanamine (BEA)hydrobromide causes a reproducible model renal papillary necrosis (RPN) within [24][25][26][27][28] hr that has been characterized in terms offunctional changes and some morphology (1,13,15,24). This BEA-induced lesion has allowed the progression of RPN to be studied and shows the marked similarities between this acute model and the changes that have been reported in the clinical condition in human analgesic abusers and also in animals dosed chronically with analgesics and nonsteroidal anti-inflammatory drugs (2,3).…”