Browsing by Subject "Coronary artery"

Now showing 1 - 3 of 3
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    Dual Coronary-Pulmonary Artery Fistula in a Patient with Severe Bicuspid Aortic Valve Stenosis
    (Houston Methodist DeBakey Heart & Vascular Center, 2023-04-10) Bou Chaaya, Rody G.; Sammour, Yasser; Thakkar, Samarthkumar; Jaradat, Ziad; Gill, William J.; Batal, Omar; Medicine, School of Medicine
    A 62-year-old male presented to the emergency department with acute viral bronchitis and worsening of his chronic dyspnea on exertion. Incidentally, a murmur was detected on physical examination. Extensive work-up, including coronary computed tomography angiography, revealed a rare combination and potential association between severe bicuspid aortic valve stenosis and coronary-pulmonary artery fistulas.
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    Epicardial calcineurin-NFAT signals through Smad2 to direct coronary smooth muscle cell and arterial wall development
    (Oxford University Press, 2014-01-01) Yang, Jin; Zeini, Miriam; Lin, Chieh-Yu; Chieh-Yu, Chien-Jung; Xiong, Yiqin; Shang, Ching; Han, Pei; Li, Wei; Quertermous, Thomas; Zhou, Bin; Chang, Ching-Pin; Department of Medicine, IU School of Medicine
    AIMS: Congenital coronary artery anomalies produce serious events that include syncope, arrhythmias, myocardial infarction, or sudden death. Studying the mechanism of coronary development will contribute to the understanding of the disease and help design new diagnostic or therapeutic strategies. Here, we characterized a new calcineurin-NFAT signalling which specifically functions in the epicardium to regulate the development of smooth muscle wall of the coronary arteries. METHODS AND RESULTS: Using tissue-specific gene deletion, we found that calcineurin-NFAT signals in the embryonic epicardium to direct coronary smooth muscle cell development. The smooth muscle wall of coronary arteries fails to mature in mice with epicardial deletion of calcineurin B1 (Cnb1), and accordingly these mutant mice develop cardiac dysfunction with reduced exercise capacity. Inhibition of calcineurin at various developmental windows shows that calcineurin-NFAT signals within a narrow time window at embryonic Day 12.5-13.5 to regulate coronary smooth muscle cell development. Within the epicardium, NFAT transcriptionally activates the expression of Smad2, whose gene product is critical for transducing transforming growth factor β (TGFβ)-Alk5 signalling to control coronary development. CONCLUSION: Our findings demonstrate new spatiotemporal and molecular actions of calcineurin-NFAT that dictate coronary arterial wall development and a new mechanism by which calcineurin-NFAT integrates with TGFβ signalling during embryonic development.
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    Mechanisms underlying capsaicin effects in canine coronary artery: implications for coronary spasm
    (Oxford University Press, 2014-09-01) Hiett, S. Christopher; Owen, Meredith K.; Li, Wennan; Chen, Xingjuan; Riley, Ashley; Noblet, Jillian; Flores, Sarah; Sturek, Michael; Tune, Johnathan D.; Obukhov, Alexander G.; Department of Cellular & Integrative Physiology, IU School of Medicine
    AIMS: The TRPV1, transient receptor potential vanilloid type 1, agonist capsaicin is considered to be beneficial for cardiovascular health because it dilates coronary arteries through an endothelial-dependent mechanism and may slow atheroma progression. However, recent reports indicate that high doses of capsaicin may constrict coronary arterioles and even provoke myocardial infarction. Thus far, the mechanisms by which TRPV1 activation modulates coronary vascular tone remain poorly understood. This investigation examined whether there is a synergistic interplay between locally acting vasoconstrictive pro-inflammatory hormones (autacoids) and capsaicin effects in the coronary circulation. METHODS AND RESULTS: Experiments were performed in canine conduit coronary artery rings and isolated smooth muscle cells (CASMCs). Isometric tension measurements revealed that 1-10 μM capsaicin alone did not affect resting tension of coronary artery rings. In contrast, in endothelium-intact rings pre-contracted with a Gq/11-coupled FP/TP (prostaglandin F/thromboxane) receptor agonist, prostaglandin F2α (PGF2α; 10 μM), capsaicin first induced transient dilation that was followed by sustained contraction. In endothelium-denuded rings pre-contracted with PGF2α or thromboxane analogue U46619 (1 μM, a TP receptor agonist), capsaicin induced only sustained contraction. Blockers of the TP receptor or TRPV1 significantly inhibited capsaicin effects, but these were still observed in the presence of 50 μM nifedipine and 70 mM KCl. Capsaicin also potentiated 20 mM KCl-induced contractions. Fluorescence imaging experiments in CASMCs revealed that the Gq/11-phospholipase C (PLC)-protein kinase C (PKC) and Ca(2+)-PLC-PKC pathways are likely involved in sensitizing CASMC TRPV1 channels. CONCLUSION: Capsaicin alone does not cause contractions in conduit canine coronary artery; however, pre-treatment with pro-inflammatory prostaglandin-thromboxane agonists may unmask capsaicin's vasoconstrictive potential.