International Outgoing Fellowship Research Articles

The effects of terminal sterilization upon the biological activity and stiffness of extracellular matrix hydrogels

The effects of terminal sterilization upon the biological activity and stiffness of extracellular matrix hydrogels

Detergent decellularization methods affect the surface molecular functionality of biologic scaffolds

Detergent decellularization methods affect the surface molecular functionality of biologic scaffolds

Telemetry‐based recording of renal cortical oxygenation in conscious rats with chronic kidney disease (890.4)

Multiple forms of acute and chronic kidney disease are associated with renal tissue hypoxia. This has led to the proposition that renal hypoxia is not just a consequence of kidney disease, but rather a primary pathogenic event. Using telemetric technology to chronically measure the partial pressure of oxygen (PO2), we recorded cortical PO2 during the early stages of development of chronic kidney disease (CKD) in conscious rats. Male Wistar rats underwent 5/6 subtotal nephrectomy (n = 4) or sham (n = 4) surgery. After an initial increase, cortical PO2 values decreased in the first 2 weeks after induction of CKD and thereafter remained stable for the subsequent 6 weeks with an average reduction of 42 ± 12% compared to baseline. Sham operation had little effect on cortical PO2. The decrease in tissue PO2 in the remnant kidney occurred before proteinuria and uremia suggesting that hypoxia precedes the symptoms of CKD and therefore could be a major driver of the subsequent pathology. This is consistent with the hypothesis that kidney hypoxia is central in the pathogenesis of CKD.Grant Funding Source: EU, FP7, Marie Curie Actions, International Outgoing Fellowship

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

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.