[ERK1/2 pathway involved in the expression of ETB receptors of the culturing smooth muscle cells of rat mesenteric artery].
OBJECTIVE
To determine the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2) pathway in the expression of endothelin receptor type B (ETB) during culture.


METHODS
SB386023, a specific inhibitor for ERK1/2 pathway, was used to define the intracellular signaling pathway for the upregulation of ETB receptors and sarafotoxin 6c (S6c), a selective agonist for ETB receptors, induced contraction in isolated rat superior mesenteric arteries. The contraction was recorded by a sensitive in vitro myograph and the receptor mRNA was quantified by a real-time PCR. The phosphorylated ERK1/2 proteins were analyzed by phosphoELISA assay.


RESULTS
S6c induced strong contractile responses of the artery after culture for 24 h, while there was no response to S6c in fresh vessel segments. The enhanced contractile response to S6c paralleled with an increase of mRNA for ETB receptors. The phosphorylated ERK1/2 proteins significantly increased after culture for 3 h. After co-culture with SB386023 for 24 h, S6c-induced contractions significantly decreased with reduction of Emax from (217 +/- 14) % to (127 +/- 23) % (P <0.01). This response paralleled with a decreased level of ETB receptor mRNA.


CONCLUSIONS
ERK1/2 pathway was involved in the up-regulation of ETB receptors on smooth muscle cells isolated from rat mesenteric arteries during culture.
Luo
Guo-gang
GG
First Hospital, Xi'an, China.
Cao
Yong-xiao
YX
Xu
Cang-bao
CB
Ma
Ai-qun
AQ
Edvinsson
Lars
L
D000818:Animals; D002478:Cells, Cultured; D008297:Male; D008638:Mesenteric Arteries / Q000166:cytology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D009924:Organ Culture Techniques; D010766:Phosphorylation; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D044023:Receptor, Endothelin B / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction; D015854:Up-Regulation; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014757:Viper Venoms / Q000494:pharmacology
D012333:RNA, Messenger; D044023:Receptor, Endothelin B; D014662:Vasoconstrictor Agents; D014757:Viper Venoms; C057354:sarafotoxins s6; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3