title: Antihypertensive, vasorelaxant and inotropic effects of an ethanolic extract of the roots of Saururus chinensis.
abstract: OBJECTIVE
  The present study was performed to evaluate the cardiovascular effects of ethanolic extract of the roots of Saururus chinensis (EERSC) in rats.
  
  
  METHODS
  The effects of EERSC on the vascular responses of isolated rat aorta, the cardiac functions in isolated rat heart, and the antihypertensive effects in spontaneously hypertensive rats (SHRs) were evaluated.
  
  
  RESULTS
  In isolated rat aortic preparations, EERSC exhibited a potent vasorelaxant effect with EC(50) value of 9.1 microg/ml. This relaxation was significantly inhibited by denudation of endothelial layer or by pretreatment with N(G)-nitro-l-arginine methyl ester. In addition, the raising extracellular K(+) (45 mM), or pretreatment with tetraethylammonium (10 mM) significantly inhibited EERSC-induced vasorelaxation in endothelium-denuded aortic rings. In isolated rat hearts, EERSC significantly reduced cardiac functions such as left ventricle pressure and heart rate. In an antihypertensive study with SHRs, long-term oral administrations of EERSC decreased blood pressure of SHRs (approximately 20 mmHg).
  
  
  CONCLUSIONS
  These results suggest that chronic treatment with EERSC exerts an antihypertensive effect in SHRs, and its direct vasorelaxant properties and negative inotropic actions may contribute to reduce the elevated blood pressure.
authors.affiliation: Drug Discovery Division, Korea Research Institute of Chemical Technology, 100 Jangdong, Yuseong, Daejeon 305-343, Republic of Korea.
authors.forename: Shi Yong
authors.initials: SY
authors.lastname: Ryu
authors.forename: Kwang-Seok
authors.initials: KS
authors.lastname: Oh
authors.forename: Young Sup
authors.initials: YS
authors.lastname: Kim
authors.forename: Byung Ho
authors.initials: BH
authors.lastname: Lee
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D001013:Aorta, Thoracic / Q000187:drug effects / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D032134:Saururaceae / Q000737:chemistry*; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000959:Antihypertensive Agents; D002316:Cardiotonic Agents; D010936:Plant Extracts; D014665:Vasodilator Agents