Single-nephron adaptations to partial renal ablation in the dog.
Micropuncture and histological studies were performed in dogs to characterize single-nephron adaptations to partial renal ablation. Dogs underwent sham surgery (group 1, n = 6), three-fourths nephrectomy (group 2, n = 10), or seven-eighths nephrectomy (group 3, n = 6). Single-nephron glomerular filtration rate (SNGFR) was 71.0 +/- 4.2 nl/min in group 1, 132.5 +/- 9.6 nl/min in group 2, and 161.8 +/- 12.4 nl/min in group 3 (P less than 0.05). There were parallel increases in single-nephron glomerular plasma flow rate (GPF), with a mean value of 235.3 +/- 20.1 nl/min in group 1, 442.4 +/- 34.4 nl/min in group 2, and 569.6 +/- 73.7 nl/min in group 3 (P less than 0.05, group 1 vs. groups 2 and 3). Glomerular capillary pressure, estimated from the sum of proximal tubule stop-flow pressure and arterial oncotic pressure, was 63.2 +/- 1.9 mmHg in group 1, 73.5 +/- 2.0 mmHg in group 2, and 77.9 +/- 2.2 mmHg in group 3 (P less than 0.05, group 1 vs. groups 2 and 3). The mean glomerular transcapillary hydraulic pressure gradient (delta P) in group 2 was not different from group 1 (46.8 +/- 1.3 vs. 43.9 +/- 1.8 mmHg, NS); however, it was significantly increased in group 3 (50.0 +/- 1.4 mmHg; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Brown
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SA
Department of Physiology, College of Veterinary Medicine, University of Georgia, Athens 30602.
Finco
D R
DR
Crowell
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WA
Choat
D C
DC
Navar
L G
LG
D000222:Adaptation, Physiological; D000818:Animals; D004285:Dogs; D005260:Female; D005919:Glomerular Filtration Rate; D006439:Hemodynamics; D007677:Kidney Function Tests; D007678:Kidney Glomerulus / Q000098:blood supply / Q000473:pathology; D008297:Male; D009392:Nephrectomy / Q000379:methods; D009399:Nephrons / Q000473:pathology / Q000502:physiology*; D011677:Punctures; D012079:Renal Circulation