title: ET(A) receptor antagonist prevents blood pressure elevation and vascular remodeling in aldosterone-infused rats.
abstract: Increased endothelin-1 may be associated with elevation of blood pressure (BP) and promotion of vascular hypertrophy, especially in salt-sensitive hypertension. Mineralocorticoid hypertension has been associated with activation of the endothelin system. We evaluated whether in aldosterone-infused rats the selective endothelin type A receptor-antagonist BMS 182874 prevents BP elevation and vascular hypertrophy. Rats were infused with aldosterone (0.75 microg/h) subcutaneously via a mini-osmotic pump and were offered 1% NaCl in the drinking water+/-BMS 182874 (40 mg/kg in food) for 6 weeks. Systolic BP was monitored by the tail-cuff method, and vascular changes of mesenteric arteries were evaluated using a pressurized myograph. Aldosterone-infusion significantly increased BP to 151+/-7 mm Hg compared with controls (108+/-4 mm Hg, P<0.01). BMS 182874 normalized BP (117+/-4 mm Hg). Media cross-sectional area of aorta was significantly increased by aldosterone infusion (P<0.05), and BMS treatment normalized it (P<0.001). Aldosterone infusion increased media width and media-to-lumen ratio of mesenteric resistance arteries (17.6+/-0.4 microm and 7.5+/-0.4%) compared with controls (14.2+/-0.5 microm, P<0.01, and 5.9+/-0.1%, P<0.05). BMS 182874 normalized media and media-to-lumen ratio (15.1+/-0.6 microm and 5.7+/-0.1%, both P<0.01). In conclusion, the endothelin type A receptor antagonist attenuated BP elevation and prevented vascular remodeling or hypertrophy of aorta and mesenteric resistance arteries in aldosterone-infused rats. These results suggest a role for endothelin-1 in BP elevation and structural alterations of large and small vessels in aldosterone and salt-induced hypertension.
authors.affiliation: Clinical Research Institute of Montreal, University of Montreal, Montreal, Quebec, Canada.
authors.forename: J B
authors.initials: JB
authors.lastname: Park
authors.forename: E L
authors.initials: EL
authors.lastname: Schiffrin
mesh_terms: D000450:Aldosterone / Q000008:administration & dosage; D000818:Animals; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001011:Aorta / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D001794:Blood Pressure / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D003619:Dansyl Compounds / Q000627:therapeutic use*; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D016232:Endothelins / Q000096:biosynthesis / Q000097:blood / Q000235:genetics; D006973:Hypertension / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D006984:Hypertrophy / Q000139:chemically induced / Q000188:drug therapy / Q000473:pathology; D007263:Infusions, Parenteral; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D011188:Potassium / Q000097:blood; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D044022:Receptor, Endothelin A; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
chemical_list: D000959:Antihypertensive Agents; D003619:Dansyl Compounds; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D016232:Endothelins; D011498:Protein Precursors; D012333:RNA, Messenger; D044022:Receptor, Endothelin A; C085754:5-(dimethylamino)-N-(3,4-dimethyl-5-isoxazolyl)-1-naphthalenesulfonamide; D000450:Aldosterone; D011188:Potassium