Measurement of renal tissue oxygen tension: systematic differences between fluorescence optode and microelectrode recordings in anaesthetized rabbits.

Background/aims: The validity of fluorescence optodes for measurement of renal cortical tissue oxygen tension was tested by comparison with Clark electrodes.

Methods: We varied renal blood flow and inspired O2 content in anaesthetized rabbits while simultaneously measuring cortical tissue oxygen tension.

Results: Cortical oxygen tension varied with inspired O2 content.

Evidence that renal arterial-venous oxygen shunting contributes to dynamic regulation of renal oxygenation.

Renal blood flow (RBF) can be reduced in rats and rabbits by up to 40% without significant changes in renal tissue Po(2). We determined whether this occurs because renal oxygen consumption changes with RBF or due to some other mechanism. The relationships between RBF and renal cortical and medullary tissue P(O(2)) and renal oxygen metabolism were determined in the denervated kidneys of anesthetized rabbits under hypoxic, normoxic, and hyperoxic conditions.