肾切片中的短期缺氧与直小血管功能

Short-term hypoxia and vasa recta function in kidney slices.

作者信息

Braun Diana, Dietze Stefanie, Pahlitzsch Tamara M J, Wennysia Inggrid C, Persson Pontus B, Ludwig Marion, Patzak Andreas

机构信息

Institute of Vegetative Physiology, Charité-Universitätsmedizin Berlin, Germany.

出版信息

Clin Hemorheol Microcirc. 2017;67(3-4):475-484. doi: 10.3233/CH-179230.

DOI:10.3233/CH-179230

PMID:28922144

Abstract

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.

摘要

背景

直小血管降支（DVR）为肾外髓质内部供血，该区域存在缺氧损伤风险。

目的

我们假设DVR在缺氧/复氧（H/R）后血管反应性增加，这可能导致缺血事件后髓质灌注减少。

方法

使用来自SD大鼠的新鲜肾切片（200μm）进行功能实验。采用TUNEL检测和苏木精-伊红染色评估切片活力。肾切片用混合气或缺氧（1% O2）处理60或90分钟，在用混合气复氧后，通过微分干涉差显微镜记录对血管紧张素II（10-7 M）的血管反应性。在铁灌注分离的直小血管中测定一氧化氮合酶（NOS）和烟酰胺腺嘌呤二核苷酸磷酸（NADPH）酶mRNA的表达。