Mesenteric arteries responsiveness to acute variations of wall shear stress is impaired in rats with liver cirrhosis.
Summary of "Mesenteric arteries responsiveness to acute variations of wall shear stress is impaired in rats with liver cirrhosis."
Abstract Objective. In liver cirrhosis, excessive splanchnic vasodilation is due to abnormal synthesis of endogenous vasodilators and to decreased sensitivity to vasoconstrictors. The role of mechanical stimuli such as wall shear stress (WSS) on splanchnic circulation remains unclear. The aim of this study was to assess the vasodilation induced by wall shear stress (WSS) and acute changes in blood flow in the mesenteric arteries in an experimental model of liver cirrhosis. Materials and Methods. The effect of acute changes in intraluminal flow (0, 10, and 20 μl/min) and WSS on the diameter of the mesenteric arteries (diameters <500 μm) of control and cirrhotic rats was assessed, at baseline and after the inhibition of nitric oxide synthase, cyclooxygenase and hemeoxygenase. Concentration-response curves to phenylephrine were also obtained. Results. In controls, the increase in intraluminal flow led to a significant increase in arterial diameter (p < 0.05), while WSS remained stable; the effect was maintained in vessels pre-constricted with phenylephrine, blocked by the exposure to indomethacin and L-NAME and restored by the subsequent addition of chromium mesoporphyrin (p < 0.05). In cirrhotic arteries, arterial diameters did not change in response to acute increase in flow, neither at baseline nor after exposure to indomethacin and L-NAME, while WSS increased (p < 0.01). Responsiveness to flow was partially restored (p < 0.05) after exposure of the arteries to chromium mesoporphyrin in addition to indomethacin and L-NAME. Conclusions. Arteries from cirrhotic rats showed an abolished responsiveness to acute variations in flow, which exposes the mesenteric endothelium to sudden variations in WSS.
Clinica Medica 5, Department of Clinical and Experimental Medicine, University of Padova , Padova , Italy.
This article was published in the following journal.
Name: Scandinavian journal of gastroenterology
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/22774919
- DOI: http://dx.doi.org/10.3109/00365521.2012.703231
Medical and Biotech [MESH] Definitions
Arteries which arise from the abdominal aorta and distribute to most of the intestines.
Mesenteric Artery, Inferior
The artery supplying nearly all the left half of the transverse colon, the whole of the descending colon, the sigmoid colon, and the greater part of the rectum. It is smaller than the superior mesenteric artery (MESENTERIC ARTERY, SUPERIOR) and arises from the aorta above its bifurcation into the common iliac arteries.
Arteries originating from the subclavian or axillary arteries and distributing to the anterior thoracic wall, mediastinal structures, diaphragm, pectoral muscles, mammary gland and the axillary aspect of the chest wall.
Arteries originating from the subclavian or axillary arteries and distributing to the anterior thoracic wall, mediastinal structures, diaphragm, pectoral muscles and mammary gland.
The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
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