Monitoring Renal Hemodynamics and Oxygenation by Invasive Probes: Experimental Protocol.

Kathleen Cantow,Bert Flemming,Mechthild Ladwig-Wiegard,Erdmann Seeliger,Andreas Pohlmann,Thoralf Niendorf

doi:10.1007/978-1-0716-0978-1_19

Abstract

Renal tissue hypoperfusion and hypoxia are early key elements in the pathophysiology of acute kidney injury of various origins, and may also promote progression from acute injury to chronic kidney disease. Here we describe methods to study control of renal hemodynamics and tissue oxygenation by means of invasive probes in anesthetized rats. Step-by-step protocols are provided for two setups, one for experiments in laboratories for integrative physiology and the other for experiments within small-animal magnetic resonance scanners.This publication is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This experimental protocol chapter is complemented by a separate chapter describing the basic concepts of quantitatively assessing renal perfusion and oxygenation with invasive probes.

Highlights

Renal tissue hypoperfusion and hypoxia have been suggested to play a pivotal role in the pathophysiology of other kidney diseases including diabetic nephropathy [14–18]
The majority of the preclinical studies that generated this concept utilized a set of invasive probes to measure renal hemodynamics and oxygenation in anaesthetized rats [12, 14–16, 19–22]
The operation table needs a steel surface to fixate the magnetic pedestals in positions required by the individual placements of the probes within the rat

Summary

Introduction

Kidney diseases are a global health burden with steadily increasing incidence [1–5]. Animal studies indicate that acute kidney injuries (AKI) of various origins share one common link in the pathophysiological chain of events, leading to AKI, as well as to progression from AKI to chronic kidney diseases (CKD): imbalance between renal oxygen delivery and oxygen demand [3, 6– 13]. The majority of the preclinical studies that generated this concept utilized a set of invasive probes to measure renal hemodynamics and oxygenation in anaesthetized rats [12, 14–16, 19–22]. Realizing the need of tracking invasive physiological parameters and MR parameters simultaneously for the same kidney, an integrated multimodality approach designated as MR-PHYSIOL was developed by our group [24, 33, 38]. It combines the measurements by the invasive probes described above

Surgical Preparation

Magnetic Resonance Imaging (for MR-PHYSIOL)

Test Interventions due to its superior SNR when compared with the transmit/ receive volume coil

Experimental Procedures

End of Experiment experiment

Data Analysis