Electrical field stimulation‐induced vasorelaxation responses decreased in anterior and middle cerebral arteries of endotoxemic rats

Abstract

IntroductionEndotoxic shock is characterized by vascular dysfunction, hypotension and multiple organ dysfunction. Loss of vascular tone is a key factor responsible for death in endotoxic shock. Perivascular innervation has an important role in the regulation of vascular tone. Neural control of the arteries is mediated by adrenergic and nitrergic neurons. The nitrergic component is dominant in brain arteries while adrenergic component is dominant in mesenteric arteries. Lipopolysaccharide (LPS) alters the electrical field stimulation (EFS) responses in mesenteric arteries in vitro. Our aim is to study the alterations of EFS responses of cerebral and mesenteric arteries in endotoxemia in rats.Material and MethodsLPS (10 mg/kg) were given intraperitoneally to rats to make an animal model os sepsis. Rats were anesthetized with gaseous carbon dioxide and decapitated 20 hours after injection, Basilar, anterior cerebral, middle cerebral and 3rd branch of mesenteric arteries were isolated and mounted in a wire myograph covered with platinum electrodes. After U46619 precontraction, frequency‐dependent EFS responses were obtained using a constant current stimulator.ResultsHigh K+ responses did not change in brain and peripheral arteries. EFS‐dependent vasorelaxation responses decreased in anterior and middle cerebral arteries in endotoxemic rats. EFS‐induced vasorelaxation responses of basilar artery and vasoconstriction responses of mesenteric arteries did not change in endotoxemic rats.ConclusionsIn this study we demonstrate for the first time that EFS‐induced vasorelaxation responses of some cerebral arteries decreased in endotoxemic rats. This EFS‐dependent alterations could be explained by degeneration of perivascular innervations or an imbalance between adrenergic and nitrergic neurons.Support or Funding InformationThis study was funded by Hacettepe University Scientific Research Projects Coordination Unit (TSA‐2017‐12848).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.