Telemetry‐based oxygen sensor to continuously monitor renal cortical oxygenation in the conscious rat

Abstract

Multiple forms of acute and chronic kidney disease are associated with renal tissue hypoxia. Yet the precise roles of hypoxia in the initiation and progression of kidney disease remain unresolved. A major technical limitation has been the absence of methods allowing long‐term measurement of kidney tissue oxygen concentration in unrestrained animals. Previously we developed a fully implantable telemetric method for the measurement of tissue oxygen concentration in the renal medulla of freely moving rats, using carbon past electrodes (CPEs). Using this CPE‐telemetry system we continuously recorded tissue oxygen concentration in the renal cortex for 3 weeks in rats. Oxygen values were stable over time and comparable between animals. It also provided reproducible responses to systemic hypoxia and hyperoxia over this time period, and these responses were similar to those previously observed in the renal medulla. There was little evidence of fibrosis or scarring after three weeks of electrode implantation. This new technology provides, for the first time, the opportunity to examine the temporal relationships between tissue hypoxia in different renal compartments and the progression of renal disease. EU, FP7, Marie Curie Actions, International Outgoing Fellowship.