Characterization and modulation of EDHF‐mediated relaxations in the rat isolated superior mesenteric arterial bed

• Published in: British journal of pharmacology 1997-04, Vol.120 (8), p.1431-1438
• Main Authors: Mcculloch, Audrey I., Bottrill, Fiona E., Randall, Michael D., Robin Hiley, C.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Biological Factors - pharmacology; Blood vessels and receptors; carbachol; Carbachol - pharmacology; clotrimazole; Clotrimazole - pharmacology; cyclic GMP; Cyclic GMP - analogs & derivatives; Cyclic GMP - pharmacology; Drug Interactions; endothelium; endothelium‐derived hyperpolarizing factor (EDHF); Enzyme Inhibitors - pharmacology; Fundamental and applied biological sciences. Psychology; Glyburide - pharmacology; In Vitro Techniques; Male; Mesenteric arterial bed; Mesenteric Arteries - drug effects; Mesenteric Arteries - physiology; Muscarinic Agonists - pharmacology; Muscle Relaxation - drug effects; NG-Nitroarginine Methyl Ester - pharmacology; NG‐nitro‐l‐arginine methyl ester (l‐NAME); nitric oxide; Nitric Oxide Synthase - antagonists & inhibitors; potassium channels; Rats; Rats, Wistar; Tetraethylammonium; tetraethylammonium (TEA); Tetraethylammonium Compounds - pharmacology; Vertebrates: cardiovascular system
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1038/sj.bjp.0701066

We have used the isolated, buffer‐perfused, mesenteric arterial bed of the rat (preconstricted with methoxamine or 60 mm K+) to characterize nitric oxide (NO)‐independent vasorelaxation which is thought to be mediated by the endothelium‐derived hyperpolarizing factor (EDHF). The muscarinic agonists carbachol, acetylcholine (ACh) and methacholine caused dose‐related relaxations in preconstricted preparations with ED50 values of 0.18±0.04 nmol (n=8), 0.05±0.02 nmol (n=6) and 0.26±0.16 nmol (n=5), respectively. In the same preparations NG‐nitro‐l‐arginine methyl ester (l‐NAME, 100 μm) significantly (P