title: Endothelin-1 stimulates bile acid secretion and vesicular transport in the isolated perfused rat liver.
abstract: The effects of endothelin (ET) on portal pressure and bile secretion were examined using isolated perfused rat liver and rat hepatocyte preparations. ET-1 raised portal pressure dose dependently; administration at a high dose (10(-9) mol) induced a > 200% increase along with reduced bile flow and decreased secretion of bile acid and phospholipids. However, a low dose (10(-10) mol) of ET-1 brought about a < 100% portal pressure rise, enhanced both bile flow and excretion of bile acid and phospholipids, and significantly increased transfer of preadministered horseradish peroxidase (HRP) into bile. In addition, values for Ca2+ concentrations, examined by indo 1 fluorescence, were elevated in isolated hepatocytes after administration of ET-1. Papaverine suppressed the low-dose ET-1 stimulation effects on both portal pressure and bile secretion. Moreover, it also reduced the HRP excretion and suppressed intracellular Ca2+ release. This study demonstrated that ET-1 stimulates vesicular transport, probably via promotion of intracellular Ca2+ release, and, as a result, increases bile acid-dependent bile flow.
authors.affiliation: First Department of Internal Medicine, Nagoya City University Medical School, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Katagiri
authors.forename: M
authors.initials: M
authors.lastname: Hoshino
authors.forename: T
authors.initials: T
authors.lastname: Hayakawa
authors.forename: K
authors.initials: K
authors.lastname: Tsukada
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism / Q000502:physiology; D001647:Bile Acids and Salts / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D016232:Endothelins / Q000494:pharmacology*; D006735:Horseradish Peroxidase / Q000378:metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008102:Liver Circulation / Q000187:drug effects; D008297:Male; D010208:Papaverine / Q000494:pharmacology; D010477:Perfusion; D010743:Phospholipids / Q000378:metabolism; D011169:Portal Vein / Q000187:drug effects; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D001647:Bile Acids and Salts; D016232:Endothelins; D010743:Phospholipids; D010208:Papaverine; D006735:Horseradish Peroxidase