title: A physiologically relevant atherogenic diet causes severe endothelial dysfunction within 4 weeks in rabbit.
abstract: A physiological atherogenic human diet consists of 0.1% cholesterol, fat, as well as high levels of methionine, which is the precursor to homocysteine. The pathological effects of a diet enriched with physiologically high levels of cholesterol, methionine and fat over a short period on the aorta are unknown. In this regard, we sought to determine the effects of a 0.1% cholesterol diet in combination with a 1% methionine over a 4-week period on endothelial function and artery pathology and the expression of endothelial nitric oxide synthase as well as nitrosative stress by nitrotyrosine (NT), oxidative stress by heat shock protein 70 (HSP70) and endoplasmic reticulum stress by glucose regulated protein 78 (GRP78). Rabbits were fed for 4 weeks a diet supplemented with 1% methionine + 0.1% cholesterol + 5% peanut oil (MC). The endothelial function of the abdominal aorta was examined using organ bath techniques, atherosclerosis determined in each artery by microscopy and eNOS, NT, GRP78 and HSP70 by standard immunohistochemistry. Endothelium dependent relaxation in response to acetylcholine significantly decreased by 63% at 1 muM acetylcholine (P < 0.001) compared with control arteries. There was no evidence of atherosclerosis formation in any artery studied, however, eNOS, NT and GRP78 was clearly present in all arteries studied but HSP70 was not easily detectable. Severe endothelial dysfunction is present in the abdominal aorta of rabbits within 4 weeks of physiological dietary manipulation, possibly due to NT formation and endoplasmic reticulum stress. This model could be used to study the early onset of endothelial dysfunction prior to the initiation of atherosclerosis.
authors.affiliation: Departments of Cardiology and Medicine, University of Melbourne, Austin Health, Australia.
authors.forename: Sudarshan
authors.initials: S
authors.lastname: Rai
authors.forename: David L
authors.initials: DL
authors.lastname: Hare
authors.forename: Anthony
authors.initials: A
authors.lastname: Zulli
mesh_terms: D000109:Acetylcholine / Q000008:administration & dosage; D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology / Q000503:physiopathology*; D001018:Aortic Diseases / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology*; D002784:Cholesterol / Q000097:blood; D002791:Cholesterol, Dietary; D004036:Diet, Atherogenic; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D004730:Endothelium, Vascular / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000008:administration & dosage; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D011817:Rabbits; D012720:Severity of Illness Index; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D002791:Cholesterol, Dietary; D000091342:Endoplasmic Reticulum Chaperone BiP; D018840:HSP70 Heat-Shock Proteins; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D014665:Vasodilator Agents; C002744:3-nitrotyrosine; D014443:Tyrosine; D002784:Cholesterol; D008715:Methionine; D052250:Nitric Oxide Synthase Type III; D000109:Acetylcholine