Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Long-term measurement of renal cortical and medullary tissue oxygenation and perfusion in unanesthetized sheep
Author: Calzavacca, P.
Evans, R.
Bailey, M.
Lankadeva, Y.
Bellomo, R.
May, C.
Citation: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, 2015; 308(10):R832-R839
Publisher: American Physiological Society
Issue Date: 2015
ISSN: 0363-6119
Statement of
Paolo Calzavacca, Roger G. Evans, Michael Bailey, Yugeesh R. Lankadeva, Rinaldo Bellomo and Clive N. May
Abstract: The role of renal cortical and medullary hypoxia in the development of acute kidney injury is controversial, partly due to a lack of techniques for the long-term measurement of intrarenal oxygenation and perfusion in conscious animals. We have, therefore, developed a methodology to chronically implant combination probes to chronically measure renal cortical and medullary tissue perfusion and oxygen tension (tPO2) in conscious sheep and evaluated their responsiveness and reliability. A transit-time flow probe and a vascular occluder were surgically implanted on the left renal artery. At the same operation, dual fiber-optic probes, comprising a fluorescence optode to measure tPO2 and a laser-Doppler probe to assess tissue perfusion, were inserted into the renal cortex and medulla. In recovered conscious sheep (n = 8) breathing room air, mean 24-h cortical and medullary tPO2 were similar (31.4 ± 0.6 and 29.7 ± 0.7 mmHg, respectively). In the renal cortex and medulla, a 20% reduction in renal blood flow (RBF) decreased perfusion (14.6 ± 8.6 and 41.2 ± 8.5%, respectively) and oxygenation (48.1 ± 8.5 and 72.4 ± 8.5%, respectively), with greater decreases during a 50% reduction in RBF. At autopsy, minimal fibrosis was observed around the probes. In summary, we have developed a technique to chronically implant fiber-optic probes in the renal cortex and medulla for recording tissue perfusion and oxygenation over many days. In normal resting conscious sheep, cortical and medullary tPO2 were similar. The responses to and recovery from renal artery occlusion, together with the consistent measurements over a 24-h period, demonstrate the responsiveness and stability of the probes.
Keywords: Renal blood flow; kidney oxygenation; renal artery occlusion; perfusion; tissue oxygen tension
Rights: © 2015 the American Physiological Society.
RMID: 0030115349
DOI: 10.1152/ajpregu.00515.2014
Grant ID:
Appears in Collections:Medicine publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.