title: Nature of the renal injury following total renal ischemia in man.
abstract: The effects of total renal ischemia (TRI) of 15-87 min duration due to suprarenal clamping of the aorta were studied in 15 mannitol-treated patients undergoing abdominal aortic surgery. 15 patients undergoing similar surgery but requiring only infrarenal clamping served as controls. 1-2 h following TRI, GFR was reduced to only 39% of that in controls, 23 +/- 5 vs. 59 +/- 7 ml/min (P less than 0.001). This could not be ascribed to impaired renal plasma flow (RPF), which was mildly reduced to 331 +/- 71 and was not different from the value in controls, 407 +/- 66 ml/min. However, impaired PAH extraction (43 +/- 7%) and isosthenuria, not present in controls, suggest a primary role for tubular injury in lowering GFR at this time. 24 h following TRI, the GFR remained depressed below controls, 45 +/- 8 vs. 84 +/- 8 ml/min (P less than 0.005), while the transglomerular sieving of neutral dextrans was significantly enhanced (radius interval, 24-40 A). A theoretical analysis of transcapillary solute exchange revealed that these findings could be largely explained by a selective reduction of either RPF (-61%) or of transmembrane hydraulic pressure difference (-18%) below control values. Alternately, a combination of these two factors with changes of smaller magnitude could explain the findings. In contrast, a selective increase in oncotic pressure or decrease of the glomerular ultrafiltration coefficient could be excluded as a cause of hypofiltration 24 h after TRI. These observations lead us to suggest that the transient azotemia observed following TRI is due to a self-limited injury to the nephron that is identical to that seen in overt and sustained forms of acute renal failure.
mesh_terms: D000368:Aged; D001012:Aorta, Abdominal / Q000601:surgery*; D003250:Constriction; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007444:Inulin; D007511:Ischemia / Q000209:etiology / Q000503:physiopathology*; D007668:Kidney / Q000098:blood supply* / Q000503:physiopathology; D007678:Kidney Glomerulus / Q000503:physiopathology; D008297:Male; D008353:Mannitol / Q000627:therapeutic use; D008875:Middle Aged; D012079:Renal Circulation; D013997:Time Factors; D010130:p-Aminohippuric Acid
chemical_list: D008353:Mannitol; D007444:Inulin; D010130:p-Aminohippuric Acid