J Anesth Perioper Med. 2016;3(4):177-184. https://doi.org/10.24015/ebcmed.japm.2016.0023

Mineralocorticoid Receptor, A Promising Target for Improving Management of Low Back Pain by Epidural Steroid Injections

Shaimaa I.A. Ibrahim1,2, Judith A. Strong1, and Jun-Ming Zhang1

From 1Pain Research Center, Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, USA; 2Graduate Program in Molecular, Cellular, and Biochemical Pharmacology, University of Cincinnati, Cincinnati, USA.

Correspondence to Dr. Jun-Ming Zhang at jun-ming.zhang@uc.edu.

EBCMED ID: ebcmed.japm.2016.0023 DOI: 10.24015/ebcmed.japm.2016.0023


Abstract

Aim of review
Low back pain is a major health problem in United States and worldwide. In this review, we aim to show that mineralocorticoid receptor (MR) activation has a critical role in the initiation of immune and inflammatory responses, which in turn can impact the effectiveness of the currently used steroids for epidural injections in low back pain management since most steroids activate MR in addition to the primary target, glucocorticoid receptor (GR). Moreover, we would like to determine some of the benefits of blocking the MR- induced negative effects. Overall, we propose a novel therapeutic approach for low back pain management by using a combination of a MR antagonist and a GR agonist in the epidural injections.

Method
We will first introduce the societal cost of low back pain and discuss how epidural steroid injections became a popular treatment for this condition. We will then describe several preclinical models used for the study of low back pain conditions and the findings with respect to the role of MR in the development of inflammatory low back pain.

Recent findings
MR has pro-inflammatory effects in many tissues which can counteract the anti-inflammatory effects induced by GR activation. Blocking MR using the selective MR antagonist eplerenone can reduce pain and sensory neuron excitability in experimental models of low back pain. Moreover, combining the MR antagonist with clinically used steroids is more effective in reducing pain behaviors than using the steroids alone.

Summary
MR antagonists are promising candidates to increase the effectiveness of currently used steroids. Since the activation of the MR is evident in preclinical models of low back pain, blocking its deleterious effects can be beneficial in managing inflammatory pain conditions.

Article Type
Review Article

Declaration of Interests
All authors have no other financial support and potential conflicts of interest for this work.

Acknowledgements
This work is supported in part by National Institutes of Health grants AR0068989, NS045594 and NS055860.

This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.