The morphology of the renal microvasculature in glycerol- and gentamicin-induced acute renal failure.
To elucidate abnormalities in the renal microvasculature that could account for the functional disturbances occurring in two well-established models of acute renal failure, we gave rats a single intramuscular injection of glycerol (50%, 10 ml/kg) or daily subcutaneous doses of gentamicin (100 mg/kg/day). Afferent arteriolar diameters were determined by measuring methacrylate vascular casts with SEM. The filtration barrier was examined by both SEM and TEM. The EF area was quantitated. By 3 hr, the glycerol treatment markedly decreased PADs and DADs (PAD 19.1 to 12.0 micrometers, DAD 13.8 to 7.4 micrometers, p less than 0.05). The changes were similar for both inner and outer cortical regions. By 3 days the vasoconstriction was alleviated; however, renal failure persisted. At that time, however, EF area was decreased to 43% of normal. After 10 days of gentamicin treatment, only minimal vasoconstriction occurred in the outer cortex; however, EF area was decreased to a similar degree as observed with the 3-day glycerol-treated animals. There are two phases to glycerol-induced acute renal failure. The first phase (described as readily reversible) is characterized by intense vasoconstriction. The second phase, which is not immediately reversible, is associated with a decreased EF area. Smaller outer cortical afferent arterioles and a decreased fenestral diameter and density of the glomerular endothelium are seen only after gentamicin-induced renal failure is well established (after 10 days of treatment).
D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000473:pathology; D000818:Animals; D003404:Creatinine / Q000378:metabolism; D005839:Gentamicins / Q000633:toxicity; D005990:Glycerol / Q000633:toxicity; D007672:Kidney Cortex / Q000648:ultrastructure; D007678:Kidney Glomerulus / Q000648:ultrastructure; D008297:Male; D008954:Models, Biological; D051381:Rats; D011919:Rats, Inbred Strains; D012077:Renal Artery / Q000187:drug effects / Q000473:pathology*
D005839:Gentamicins; D003404:Creatinine; D005990:Glycerol