Endothelium-derived 2-arachidonylglycerol: an intermediate in vasodilatory eicosanoid release in bovine coronary arteries
| Autor: | Cecilia J. Hillard, Sarah B. Hittner, John R. Falck, D. Sudarshan Reddy, William B. Campbell, Kasem Nithipatikom, David V. Baewer, Kathryn M. Gauthier |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
medicine.medical_specialty
Endothelium-derived hyperpolarizing factor Endothelium Physiology Vasodilation Prostacyclin Arachidonic Acids Glycerides chemistry.chemical_compound 8 11 14-Eicosatrienoic Acid Physiology (medical) Internal medicine Hydroxyeicosatetraenoic Acids medicine Animals Carbon Radioisotopes Cells Cultured Arachidonic Acid Coronary Vessels Endocrinology medicine.anatomical_structure chemistry Eicosanoid Circulatory system Cattle Arachidonic acid Endothelium Vascular Cardiology and Cardiovascular Medicine Acetylcholine Endocannabinoids medicine.drug |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 288:H1344-H1351 |
| ISSN: | 1522-1539 0363-6135 |
| DOI: | 10.1152/ajpheart.00537.2004 |
| Popis: | Acetylcholine stimulates the release of endothelium-derived arachidonic acid (AA) metabolites including prostacyclin and epoxyeicosatrienoic acids (EETs), which relax coronary arteries. However, mechanisms of endothelial cell (EC) AA activation remain undefined. We propose that 2-arachidonylglycerol (2-AG) plays an important role in this pathway. An AA metabolite isolated from bovine coronary ECs was identified as 2-AG by mass spectrometry. In ECs pretreated with the fatty acid amidohydrolase inhibitor diazomethylarachidonyl ketone (DAK; 20 micromol/l), methacholine (10 micromol/l)-stimulated 2-AG release was blocked by the phospholipase C inhibitor U-73122 (10 micromol/l) or the diacylglycerol lipase inhibitor RHC-80267 (40 micromol/l). In U-46619-preconstricted bovine coronary arterial rings, 2-AG relaxations averaging 100% at 10 micromol/l were inhibited by endothelium removal, by DAK, by the hydrolase inhibitor methyl arachidonylfluorophosphate (10 micromol/l), by the cyclooxygenase inhibitor indomethacin (10 micromol/l), but not by the CB1 cannabinoid receptor antagonist SR-141716 (1 micromol/l). The cytochrome P-450 inhibitor SKF-525a (10 micromol/l) and the 14,15-epoxyeicosa-5Z-enoic acid EET antagonist (14,15-EEZE; 10 micromol/l) further attenuated the indomethacin-resistant relaxations. The nonhydrolyzable 2-AG analogs noladin ether, 2-AG amide, and 14,15-EET glycerol amide did not induce relaxation. N-nitro-L-arginine-resistant relaxations to methacholine were also inhibited by U-73122, RHC-80267, and DAK. 14,15-EET glycerol ester increased opening of large-conductance K(+) channels 12-fold in cell-attached patches of isolated smooth muscle cells and induced relaxations averaging 95%. These results suggest that methacholine stimulates EC 2-AG production through phospholipase C and diacylglycerol lipase activation. 2-AG is further hydrolyzed to AA, which is metabolized to vasoactive eicosanoids. These studies reveal a role for 2-AG in EC AA release and the regulation of coronary tone. |
| Databáze: | OpenAIRE |
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