Long-term measurement of renal cortical and medullary tissue oxygenation and perfusion in unanesthetized sheep

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-D..