Abstract 13242: Important Roles of Cardiac Lymphatic System in the Regulation of Coronary Vasomotion After Drug-Eluting Stent Implantation in Pigs in Vivo

BackgroundVascular lymphatic system plays various important roles, including recruitment of inflammatory cells from the adventitia. We have previously demonstrated that adventitial inflammation plays important roles in the pathogenesis of drug-eluting stent (DES)-induced coronary hyperconstricting responses. In this study, we examined the role of coronary lymphatic system in vasomotor regulation in a porcine model of DES-induced hyperconstriction.Methods and ResultsTwelve domestic male pigs underwent cardiac lymphatic ligation or sham operation (N=6 each). Cardiac lymphatic ligation was performed at the proximal sites close to the left main trunk and the right coronary arteries. At 2 weeks after the surgery, DES was implanted into the left anterior descending coronary artery. At 4 weeks later, coronary angiography was performed to examine coronary vasomotor responses to intracoronary serotonin in vivo. After the in vivo study, stented coronary vessels were harvested to perform immunohistochemistry for LYVE-1 (lymphatic endothelial cell marker), inflammation (macrophages and IL-1β expression), Rho-kinase isoforms, Rho-kinase activity (phosphorylated form of myosin phosphatase target subunit-1 (pMYPT-1)) and Masson Trichrome (adipocytes). Coronary vasoconstricting responses at DES edges were significantly enhanced in the ligation group (P