title: Angiotensin-converting enzyme inhibition but not angiotensin II type 1 receptor antagonism augments coronary release of tissue plasminogen activator in hypertensive patients.
abstract: OBJECTIVE
  We compared the effects of perindopril and losartan on endothelium-dependent coronary vasomotor and fibrinolytic function.
  
  
  BACKGROUND
  The renin-angiotensin system regulates the vascular fibrinolytic balance. However, the effects of angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor antagonists on coronary fibrinolytic function have not been compared in hypertensive patients.
  
  
  METHODS
  Forty-five patients with hypertension were randomly assigned to three groups: 16 patients were treated with perindopril (4 mg/day) for four weeks; 15 were treated with losartan (50 mg/day) for four weeks; and 14 were not treated with either perindopril or losartan (control group). Graded doses of bradykinin (BK) (0.2, 0.6, and 2.0 microg/min) were administered into the left coronary artery. Coronary blood flow (CBF) was evaluated by Doppler flow velocity measurement.
  
  
  RESULTS
  Bradykinin induced dose-dependent increases in CBF in all groups. The increases in CBF induced by BK in the perindopril and losartan groups were significantly greater than those in the control group. Net coronary tissue-type plasminogen activator (t-PA) release was enhanced by BK in all groups, and the increase in the perindopril group was greater than that in the losartan and control groups. Bradykinin did not alter plasminogen activator inhibitor type 1 levels in any of the groups.
  
  
  CONCLUSIONS
  Perindopril and losartan similarly augment BK-induced coronary vasodilation. Perindopril may have a greater potential to enhance the BK-induced coronary release of t-PA than losartan.
authors.affiliation: First Department of Internal Medicine, Shiga University of Medical Science, Seta Tsukinowa, Otsu, Japan. tetsuyam@belle.shiga-med.ac.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Minai
authors.forename: Hajime
authors.initials: H
authors.lastname: Horie
authors.forename: Naoto
authors.initials: N
authors.lastname: Ohira
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takashima
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tarutani
authors.forename: Yo
authors.initials: Y
authors.lastname: Yasuda
authors.forename: Tomoya
authors.initials: T
authors.lastname: Ozawa
authors.forename: Shinro
authors.initials: S
authors.lastname: Matsuo
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kinoshita
authors.forename: Minoru
authors.initials: M
authors.lastname: Horie
mesh_terms: D000368:Aged; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001920:Bradykinin / Q000378:metabolism*; D003326:Coronary Circulation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000188:drug therapy* / Q000378:metabolism; D019808:Losartan / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D020913:Perindopril / Q000008:administration & dosage / Q000494:pharmacology*; D044140:Receptor, Angiotensin, Type 1; D010959:Tissue Plasminogen Activator / Q000097:blood*
chemical_list: D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D044140:Receptor, Angiotensin, Type 1; D010959:Tissue Plasminogen Activator; D019808:Losartan; D001920:Bradykinin; D020913:Perindopril