Open AccessInfluence of Connexin40 on the renal myogenic response in murine afferent arterioles
Author(s) -
Jacobsen Jens Christian B.,
Sorensen Charlotte M.
Publication year - 2015
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12416
Subject(s) - myogenic contraction , afferent arterioles , tubuloglomerular feedback , autoregulation , arteriole , nephron , chemistry , connexin , medicine , endocrinology , kidney , microcirculation , microbiology and biotechnology , anatomy , blood pressure , biology , gap junction , smooth muscle , renin–angiotensin system , intracellular
Renal autoregulation consists of two main mechanisms; the myogenic response and the tubuloglomerular feedback mechanism ( TGF ). Increases in renal perfusion pressure activate both mechanisms causing a reduction in diameter of the afferent arteriole ( AA ) resulting in stabilization of the glomerular pressure. It has previously been shown that connexin‐40 (Cx40) is essential in the renal autoregulation and mediates the TGF mechanism. The aim of this study was to characterize the myogenic properties of the AA in wild‐type and connexin‐40 knockout (Cx40 KO ) mice using both in situ diameter measurements and modeling. We hypothesized that absence of Cx40 would not per se affect myogenic properties as Cx40 is expressed primarily in the endothelium and as the myogenic response is known to be present also in isolated, endothelium‐denuded vessels. Methods used were the isolated perfused juxtamedullary nephron preparation to allow diameter measurements of the AA . A simple mathematical model of the myogenic response based on experimental parameters was implemented. Our findings show that the myogenic response is completely preserved in the AA of the Cx40 KO and if anything, the stress sensitivity of the smooth muscle cell in the vascular wall is increased rather than reduced as compared to the WT . These findings are compatible with the view of the myogenic response being primarily a local response to the local transmural pressure.