title: Serum angiotensin converting enzyme activity and response to angiotensin I in horses.
abstract: The activity of serum angiotensin converting enzyme (ACE) for healthy horses was 64 +/- 13 mUnits/ml. In vitro, equine serum ACE was sensitive to the following inhibitors (IC50): enalapril (570 nM or 215 ng/ml), captopril (190 nM or 41.3 ng/ml), and enalaprilat (6 nM or 2.1 ng/ml). The intravenous (i.v.) administration of angiotensin I to six healthy horses produced a dose proportional pressor response. The maximal increase in mean arterial pressure over baseline values was 65.6 mmHg at angiotensin I doses of 500 ng/kg bodyweight (bwt). The attenuation of this response to angiotensin I was further demonstrated in a single horse by the prior administration of enalaprilat at an i.v. dose of 8.71 micrograms/kg bwt.
authors.affiliation: Department of Pharmaceutics, College of Pharmacy, University of Georgia, Athens 30602, USA.
authors.forename: L G
authors.initials: LG
authors.lastname: Tillman
authors.forename: J N
authors.initials: JN
authors.lastname: Moore
mesh_terms: D000803:Angiotensin I / Q000008:administration & dosage / Q000494:pharmacology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002216:Captopril / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004656:Enalapril / Q000008:administration & dosage / Q000494:pharmacology; D015773:Enalaprilat / Q000008:administration & dosage / Q000494:pharmacology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006736:Horses / Q000097:blood*; D007275:Injections, Intravenous / Q000662:veterinary; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000097:blood*; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril; D000803:Angiotensin I; D002216:Captopril; D007703:Peptidyl-Dipeptidase A; D015773:Enalaprilat