Maintenance and recovery stages of postischemic acute renal failure in humans.
Postischemic injury in 38 recipients of 7-day-old cadaveric renal allografts was classified into sustained (n = 15) or recovering (n = 23) acute renal failure (ARF) according to the prevailing inulin clearance. Recipients of long-standing allografts that functioned optimally (n = 16) and living transplant donors undergoing nephrectomy (n = 10) served as functional and structural controls, respectively. A combination of physiological and morphometric techniques were used to evaluate glomerular filtration rate and its determinants 1-3 h after reperfusion and again on day 7 to elucidate the mechanism for persistent hypofiltration in ARF that is sustained. Glomerular filtration rate in the sustained ARF group on day 7 was depressed by 90% (mean +/- SD); the corresponding fall in renal plasma flow was proportionately less. Neither plasma oncotic pressure nor the single-nephron ultrafiltration coefficient differed between the sustained ARF and the control group, however. A model of glomerular ultrafiltration and a sensitivity analysis were used to compute the prevailing transcapillary hydraulic pressure gradient (DeltaP), the only remaining determinant of DeltaP. This revealed that DeltaP varied between 27 and 28 mmHg in sustained ARF and 32-38 mmHg in recovering ARF on day 7 vs. 47-54 mmHg in controls. Sustained ARF was associated with persistent tubular dilatation. We conclude that depression of DeltaP, perhaps due partially to elevated tubule pressure, is the predominant cause of hypofiltration in the maintenance stage of ARF that is sustained for 7 days.
Ramaswamy
Deepa
D
Division of Nephrology, Stanford University School of Medicine, Stanford University, Stanford, California 94305, USA.
Corrigan
Geraldine
G
Polhemus
Catherine
C
Boothroyd
Derek
D
Scandling
John
J
Sommer
F Graham
FG
Alfrey
Edward
E
Higgins
John
J
Deen
William M
WM
Olshen
Richard
R
Myers
Bryan D
BD
D058186:Acute Kidney Injury / Q000503:physiopathology*; D000293:Adolescent; D000328:Adult; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007444:Inulin / Q000493:pharmacokinetics; D007511:Ischemia / Q000503:physiopathology*; D007678:Kidney Glomerulus / Q000503:physiopathology; D016030:Kidney Transplantation / Q000502:physiology*; D007684:Kidney Tubules / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011312:Pressure; D020127:Recovery of Function / Q000502:physiology; D014184:Transplantation, Homologous
D007444:Inulin