Short-term hypoxia and vasa recta function in kidney slices
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Updated: Feb 22, 2026
Modeling Hypoxia/Reoxygenation Injury in Proximal Tubular Epithelial Cells
Published on: November 21, 2025
Diana Braun1, Stefanie Dietze1, Tamara M J Pahlitzsch1
1Institute of Vegetative Physiology, Charité-Universitätsmedizin Berlin, Germany.
Background:
Descending vasa recta (DVR) supply the inner part of outer renal medulla an area at risk for hypoxic damages.
Objective:
We hypothesize increased vasoreactivity after hypoxia/re-oxygenation (H/R) in DVR, which might contribute to the reduced medullary perfusion after an ischemic event.
Methods:
Live kidney slices (200μm) from SD rats were used for functional experiments. TUNEL assay and H&E staining were used to estimate slice viability. Kidney slices were treated with carbogen or hypoxia (1% O2) for 60 or 90 min and vasoreactivity to Ang II (10-7 M) was recorded by DIC microscopy after re-oxygenation with carbogen. Expression of NOS and NADPH enzymes mRNA were determined in iron-perfusion isolated VR.
Results:
Percentage of apoptotic cells increased in control and H/R after 90 min in the medulla. Ang II- induced constriction of DVR was reduced after 90 min in control (compared to 60 min), but not after H/R. NOS enzymes mRNA expression levels decreased over 90 min hypoxia.
Conclusions:
Increased reactivity of DVR to Ang II after H/R compared to control (90 min) suggest a role of DVR in renal ischemia/reperfusion injury.
