Abstract
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 (Cx40KO) 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, endotheliumdenuded
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 Cx40KO 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.
| Original language | English |
|---|---|
| Article number | e12416 |
| Journal | Physiological Reports |
| Volume | 3 |
| Issue number | 5 |
| Pages (from-to) | 1-12 |
| Number of pages | 12 |
| ISSN | 2051-817X |
| DOIs | |
| Publication status | Published - 25 May 2015 |