title: Flow-mediated release of nitric oxide from lymphatic endothelial cells of pressurized canine thoracic duct.
abstract: We examined the effects of flow on lymphatic endothelial cells by using conventional cascade preparations of isolated coronary arteries without intact endothelium. The pressurized thoracic ducts were intraluminally perfused at a constant flow rate ranging from 0.5 to 2.0 ml/min. A linear relationship was observed between the flow rate and the normalized amount of relaxing substance(s) released from the lymphatic endothelial cells. Thus the flow rate of 2.0 ml/min produced approximately 39% of sodium nitroprusside (SNP)-produced maximal relaxation in the cascade arterial rings. The acetylcholine (ACh, 10(-5) M)- and flow-induced relaxations of the cascade arterial rings were completely reduced by the mechanical rubbing of lymphatic endothelial cells in the pressurized lymph vessels. Pretreatment with 5 x 10(-5) M N(G)-nitro-L-arginine methyl ester (L-NAME) on the lymphatic endothelial cells caused a significant reduction of the ACh- and flow-induced vasodilations of the cascade arterial rings. Pretreatment with 10(-5) M indomethacin on the lymphatic endothelial cells produced no significant effect on the ACh- and flow-induced vasodilations. These findings suggest that lymphatic endothelial cells of canine thoracic ducts can produce and release endogenous nitric oxide by stimulation of flow (approximately 2.0 ml/min).
authors.affiliation: The 1st Department of Physiology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621 Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Tsunemoto
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Ikomi
authors.forename: Toshio
authors.initials: T
authors.lastname: Ohhashi
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001681:Biological Assay; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004285:Dogs; D004338:Drug Combinations; D042783:Endothelial Cells / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008196:Lymph / Q000502:physiology*; D008208:Lymphatic System / Q000378:metabolism*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D011312:Pressure; D013314:Stress, Mechanical; D013897:Thoracic Duct / Q000378:metabolism*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D016861:Cyclooxygenase Inhibitors; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D014665:Vasodilator Agents; D009569:Nitric Oxide; D001120:Arginine; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin