Cyclic ADP ribose-mediated Ca2+ signaling in mediating endothelial nitric oxide production in bovine coronary arteries

• Published in: American journal of physiology. Heart and circulatory physiology 2006-03, Vol.290 (3), p.H1172-H1181
• Main Authors: Zhang, Guo, Teggatz, Eric G, Zhang, Andrew Y, Koeberl, Matthew J, Yi, Fan, Chen, Li, Li, Pin-Lan
• Format: Article
• Language: English
• Subjects: Animals; Calcium - metabolism; Calcium Signaling - physiology; Cattle; Cells, Cultured; Coronary Vessels - physiology; Cyclic ADP-Ribose - metabolism; Endothelial Cells - physiology; Endothelium, Vascular - physiology; In Vitro Techniques; Nitric Oxide - metabolism; Signal Transduction - physiology
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.00441.2005

1 Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia; 2 Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin; and 3 Research Center of Experimental Medicine, Guangxi Autonumous Region People's Hospital, Nanning, Guangxi, People's Republic of China Submitted 2 May 2005 ; accepted in final form 19 October 2005 The present study tested the hypothesis that cyclic ADP ribose (cADPR) serves as a novel second messenger to mediate intracellular Ca 2+ mobilization in coronary arterial endothelial cells (CAECs) and thereby contributes to endothelium-dependent vasodilation. In isolated and perfused small bovine coronary arteries, bradykinin (BK)-induced concentration-dependent vasodilation was significantly attenuated by 8-bromo-cADPR (a cell-permeable cADPR antagonist), ryanodine (an antagonist of ryanodine receptors), or nicotinamide (an ADP-ribosyl cyclase inhibitor). By in situ simultaneously fluorescent monitoring, Ca 2+ transient and nitric oxide (NO) levels in the intact coronary arterial endothelium preparation, 8-bromo-cADPR (30 µM), ryanodine (50 µM), and nicotinamide (6 mM) substantially attenuated BK (1 µM)-induced increase in intracellular [Ca 2+ ] by 78%, 80%, and 74%, respectively, whereas these compounds significantly blocked BK-induced NO increase by about 80%, and inositol 1,4,5-trisphosphate receptor blockade with 2-aminethoxydiphenyl borate (50 µM) only blunted BK-induced Ca 2+ -NO signaling by about 30%. With the use of cADPR-cycling assay, it was found that inhibition of ADP-ribosyl cyclase by nicotinamide substantially blocked BK-induced intracellular cADPR production. Furthermore, HPLC analysis showed that the conversion rate of -nicotinamide guanine dinucleotide into cyclic GDP ribose dramatically increased by stimulation with BK, which was blockable by nicotinamide. However, U-73122, a phospholipase C inhibitor, had no effect on this BK-induced increase in ADP-ribosyl cyclase activity for cADPR production. In conclusion, these results suggest that cADPR importantly contributes to BK- and A-23187-induced NO production and vasodilator response in coronary arteries through its Ca 2+ signaling mechanism in CAECs. nucleotide; vasodilation; endothelium; endothelium-derived relaxing factor Address for reprint requests and other correspondence: P.-L. Li, Dept. of Pharmacology & Toxicology, Medical College of Virginia, 410 N 12th St., Ri