Flow-dependent regulation of vascular function and gene expression in rat superior mesenteric artery.
BACKGROUND
Mesenteric artery thrombosis is prone to occur at specific arterial regions with different fluid flow patterns, yet mechanistic links between blood flow and vascular function remain unclear. This study aimd to investigate the role of blood flow in regulation of vascular function and gene expression in rats.


METHODS
Isometric tension was recorded in wire myograph to examine vascular function of specific regions (trunk parts and proximal parts from the origin) with different blood flow in superior mesenteric artery (SMA). Endothelial nitric oxide syntheses (eNOS), phosphorylated-eNOS (p-eNOS), serine-threonine kinase Akt and phosphorylated-Akt (p-Akt) protein expressions in SMA were examined by Western blotting. Significance was analyzed using a Student's t test or analysis of variance (ANOVA) followed by a Dunnett's multiple-comparison post hoc test.


RESULTS
Compared with trunks, proximal parts exhibited severely impaired relaxant responses to acetylcholine (Ach) (1 nmol/L to 10 micromol/L) (P < 0.01). p-eNOS and p-Akt protein levels were significantly reduced in proximal parts of SMA (0.37 +/- 0.03, 0.42 +/- 0.03 respectively) versus trunk parts (0.82 +/- 0.03, 0.72 +/- 0.03 respectively, both P < 0.05) while total eNOS and Akt expressions remain comparable in both regions by Western blotting analysis (0.70 +/- 0.03 vs 0.82 +/- 0.03; 0.70 +/- 0.03 vs 0.77 +/- 0.03 respectively, both P > 0.05).


CONCLUSIONS
Critical components that drive the vascular function and influence the localization of mesenteric artery thrombosis are flow-responsive elements within the vascular endothelium.
Xia
Shang
S
Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China.
Deng
Chang-sheng
CS
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D017538:Mesenteric Artery, Superior / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D033081:Shear Strength; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D051057:Proto-Oncogene Proteins c-akt; D000109:Acetylcholine