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Role of adenosine in muscle afferent TRPV1‐engaged reflex sympathetic response
Author(s) -
Li Jianhua,
Xing Jihong,
Sinoway Lawrence
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.610.1
Subject(s) - trpv1 , adenosine , reflex , capsaicin , medicine , adenosine receptor , endocrinology , adenosine a1 receptor , agonist , dorsal root ganglion , hindlimb , chemistry , receptor , anatomy , transient receptor potential channel , dorsum
Capsaicin injected into the arterial blood supply of the hindlimb muscles of rats increases the renal sympathetic nerve activity (RSNA) and blood pressure via a reflex mechanism. The responses are altered in disease states such as heart failure and hindlimb muscle ischemia. The purpose of this study was to examine the role adenosine plays in modulating metabolite‐sensitive receptor potential vanilloid type 1 (TRPV1) receptors/capsaicin receptor activity. Our results show that the prior application of 1 μM of adenosine significantly attenuated capsaicin‐induced current of the dorsal root ganglion neurons innervating muscles (current amplitude: 2.37±0.35 nA in 19 control cells and 0.56±0.15 nA in 19 cells with prior adenosine, P <0.05). 100 µM adenosine injected into the femoral artery had an inhibitory effect on the reflex RSNA response induced by capsaicin in six rats. Arterial injection of adenosine analogue CGS21680 (A 2A subtype receptor agonist, 100 µM) significantly attenuated the reflex response in six rats. Based on these data, we speculate that adenosine is likely to inhibit muscle afferent TRPV1‐engaged reflex responses as the levels of adenosine are increased in the hindlimb muscles and/or its receptors. The role this system plays in pathologic conditions needs to be studied. (All procedures outlined in this study were performed in compliance with the rules and regulations described in the NIH Guide for the Care and Use of Laboratory Animals ).