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Gv, Luk'yantseva; Iy, Sergeev; Gn, Kopylova; Ge, Samonina; Sv, German

doi:10.1023/a:1013646723338

Cited by 6 publications

(1 citation statement)

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“…This observation is consistent with previous results showing the capacity of exogenously added amylin to impair endothelium-dependent relaxation of rat aorta and mesenteric arteries [ 27 ]. Former reports had suggested a vasodilatory capacity of amylin but these studies were carried out with concentrations of amylin largely above those achievable in plasma, even in insulin resistance, an effect related to its agonistic activity on calcitonin gene-related peptide (CGRP) at such elevated concentrations [ 41 , 42 ], that does not seem to be mediated by NO or the endothelium [ 43 ].…”

Section: Discussionmentioning

confidence: 99%

Differential Effect of Amylin on Endothelial-Dependent Vasodilation in Mesenteric Arteries from Control and Insulin Resistant Rats

et al. 2015

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Insulin resistance (IR) is frequently associated with endothelial dysfunction and has been proposed to play a major role in cardiovascular disease (CVD). On the other hand, amylin has long been related to IR. However the role of amylin in the vascular dysfunction associated to IR is not well addressed. Therefore, the aim of the study was to assess the effect of acute treatment with amylin on endothelium-dependent vasodilation of isolated mesenteric arteries from control (CR) and insulin resistant (IRR) rats and to evaluate the possible mechanisms involved. Five week-old male Wistar rats received 20% D-fructose dissolved in drinking water for 8 weeks and were compared with age-matched CR. Plasmatic levels of glucose, insulin and amylin were measured. Mesenteric microvessels were dissected and mounted in wire myographs to evaluate endothelium-dependent vasodilation to acetylcholine. IRR displayed a significant increase in plasmatic levels of glucose, insulin and amylin and reduced endothelium-dependent relaxation when compared to CR. Acute treatment of mesenteric arteries with r-amylin (40 pM) deteriorated endothelium-dependent responses in CR. Amylin-induced reduction of endothelial responses was unaffected by the H2O2 scavenger, catalase, but was prevented by the extracellular superoxide scavenger, superoxide dismutase (SOD) or the NADPH oxidase inhibitor (VAS2870). By opposite, amylin failed to further inhibit the impaired relaxation in mesenteric arteries of IRR. SOD, or VAS2870, but not catalase, ameliorated the impairment of endothelium-dependent relaxation in IRR. At concentrations present in insulin resistance conditions, amylin impairs endothelium-dependent vasodilation in mircrovessels from rats with preserved vascular function and low levels of endogenous amylin. In IRR with established endothelial dysfunction and elevated levels of amylin, additional exposure to this peptide has no effect on endothelial vasodilation. Increased superoxide generation through NADPH oxidase activity may be a common link involved in the endothelial dysfunction associated to insulin resistance and to amylin exposure in CR.

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