Renal preglomerular arterial-venous O2 shunting is a structural anti-oxidant defence mechanism of the renal cortex

Paul M O'Connor, Warwick P. Anderson, Michelle M. Kett, Roger G. Evans

Research output: Contribution to journalReview article

30 Scopus citations

Abstract

1. High blood flow to the kidney facilitates a high glomerular filtration rate, but total renal O2 delivery greatly exceeds renal metabolic requirements. However, tissue PO2 in much of the renal cortex is lower than may be expected, being similar to that of other organs in which perfusion is closely matched to metabolic demand. 2. The lower than expected renal cortical PO2 is now attributed largely to diffusional shunting of as much as 50% of inflowing O2 from blood within preglomerular arterial vessels to postglomerular venous vessels. However, the functional significance of this O2 shunting remains unclear. Indeed, this mechanism may appear maladaptive, given the kidney's susceptibility to hypoxic insults. 3. We hypothesize that renal preglomerular arterial-venous O 2 shunting acts to protect the kidney from the potentially damaging consequences of tissue hyperoxia. The diffusion of O2 from arteries to veins within the kidney acts to reduce the O2 content of the blood before it is distributed to the renal microcirculation. Because high tissue PO2 may increase the production of reactive oxygen species, we suggest that renal arterial-venous O2 shunting may provide a physiological benefit to the organism by limiting O2 delivery to renal tissue, thereby reducing the risk of cellular oxidation.

Original languageEnglish (US)
Pages (from-to)637-641
Number of pages5
JournalClinical and Experimental Pharmacology and Physiology
Volume33
Issue number7
DOIs
Publication statusPublished - Jul 1 2006
Externally publishedYes

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Keywords

  • Free radicals
  • Kidney
  • Oxidative stress
  • Oxygen
  • Renal blood flow
  • Renal disease

ASJC Scopus subject areas

  • Physiology
  • Pharmacology
  • Physiology (medical)

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