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Increased myoendothelial feedback is associated with increased connexin37 and IK 1 channel expression in mesenteric arteries of diet‐induced hyperhomocysteinemic mice
Author(s) -
LooftWilson Robin C.,
Goodell Cara R.,
Mutch Christina A.,
Mutchler Stephanie M.,
Miller Kayla L.,
Guraya Monique
Publication year - 2017
Publication title -
microcirculation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.793
H-Index - 83
eISSN - 1549-8719
pISSN - 1073-9688
DOI - 10.1111/micc.12398
Subject(s) - mesenteric arteries , enos , endocrinology , medicine , electrical impedance myography , vasomotor , vasodilation , vasoconstriction , phenylephrine , prostacyclin , endothelium derived hyperpolarizing factor , potassium channel , chemistry , iberiotoxin , anatomy , artery , nitric oxide synthase , blood pressure , nitric oxide , charybdotoxin
Objective Previously, we found that diet‐induced HH cy in mice caused decreased eNOS expression and signaling in mesenteric arteries, but greatly enhanced non‐ NOS , non‐prostacyclin‐dependent vasodilation, which involves MEJ communication. To further assess whether HH cy enhances MEJ communication, this study examined endothelium‐dependent attenuation of phenylephrine‐induced vasoconstriction (myoendothelial feedback) and key molecules involved. Methods Myoendothelial feedback was examined in isolated mouse mesenteric arteries, after 6‐weeks diet‐induced HH cy, using pressure myography. Gap junction (Cx37, Cx40, Cx43), NOS ( eNOS , nNOS , iNOS ), and potassium channel ( IK 1) protein expression were measured with immunoblots, and connexin mRNA s with real‐time PCR . Contribution of nNOS + iNOS to vasomotor responses was assessed using the drug TRIM. Results Myoendothelial feedback was significantly ( P < .05) enhanced in HH cy arteries compared to control, coincident with significantly greater Cx37 and IK 1 protein and Cx37 mRNA . Cx43 protein, but not mRNA , was significantly less in HH cy, and Cx40 was not different. eNOS protein was significantly less in HH cy. nNOS and iNOS were not different. TRIM had little effect on vasomotor function. Conclusions Diet‐induced HH cy enhanced myoendothelial feedback, and increased Cx37 and IK 1 expression may contribute. nNOS or iNOS did not upregulate to compensate for decreased eNOS , and they had little involvement in vasomotor function.