Hypoxia/reoxygenation enhances murine afferent arteriolar vasoconstriction by angiotensin II.

Hypoxia/reoxygenation enhances murine afferent arteriolar vasoconstriction by angiotensin II. Am J Physiol Renal Physiol. 2017 Oct 25;:ajprenal.00252.2017 Authors: Pahlitzsch TM, Liu ZZ, Al-Masri A, Braun D, Dietze S, Persson PB, Schunck WH, Blum M, Kupsch E, Ludwig M, Patzak A Abstract We tested the hypothesis that hypoxia/reoxygenation (H/R) augments vasoreactivity to angiotensin II (Ang II). In particular, we compared an in situ live kidney slice model with isolated afferent arterioles (C57Bl6 mice) to assess the impact of tubules on microvessel response. H&E staining was used to estimate slice viability. Arterioles in the slices were located by DIC microscopy, and responses to vasoactive substances were assessed. Cytosolic calcium transients and NADPH oxidase mRNA expression were studied in isolated afferent arterioles. SOD activity was measured in live slices. Both experimental models were subjected to control and H/R treatment (60 min). Slices were further analyzed after 30, 60 and 90 min hypoxia followed by 10 or 20 min re-oxygenation. H/R resulted in enhanced necrotic tissue damage compared to control conditions. To characterize the slice model, we applied Ang II (10-7 M), NE (10-5 M), ET-1 (10-7 M) and ATP (10-4 M) reducing the initial diameter to 44.5±2.8%, 50.0±2.2%, 45.3±2.6%, and 74.1±1.8%. H/R significantly increased the Ang II response compared to control in live slices and in isolated afferent arterioles, alth...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research