Ghrelin preserves ischemia-induced vasodilation of male rat coronary vessels following beta-adrenergic receptor blockade.

Ghrelin preserves ischemia-induced vasodilation of male rat coronary vessels following beta-adrenergic receptor blockade. Endocrinology. 2018 Jan 09;: Authors: Pearson JT, Collie N, Lamberts RR, Inagaki T, Yoshimoto M, Umetani K, Davis P, Wilkins G, Jones PP, Shirai M, Schwenke DO Abstract Acute myocardial infarction (MI) triggers an adverse increase in cardiac sympathetic nerve activity (SNA). While β-adrenergic receptor (β-AR)-blockers are routinely used for the management of MI, they may also counter β-AR-mediated vasodilation of coronary vessels. We have reported that ghrelin prevents sympathetic activation following MI. Whether ghrelin modulates coronary vascular tone following MI, either through the modulation of SNA, or directly as a vasoactive mediator, has never been addressed.We utilized synchrotron microangiography to image coronary perfusion and vessel internal diameter (ID) in anesthetized Sprague Dawley rats before, and then again 30 mins after induction of an MI (left coronary artery ligation). Rats were injected with either saline or ghrelin (150 µg/kg, s.c.) immediately following the MI or sham surgery. Coronary angiograms were also recorded following β-AR blockade (propranolol, 2 mg/kg, i.v.). Finally, wire myography was used to assess the effect of ghrelin on vascular tone in isolated human internal mammary arteries (IMA). Acute MI enhanced coronary perfusion to 'non-ischemic' regions through dilation of small...
Source: Endocrinology - Category: Endocrinology Authors: Tags: Endocrinology Source Type: research