Early endothelial dysfunction in cholesterol-fed rabbits: a non-invasive in vivo ultrasound study.
BACKGROUND
Endothelial function in hypercholesterolemic rabbits is usually evaluated ex vivo on isolated aortic rings. In vivo evaluation requires invasive imaging procedures that cannot be repeated serially.


OBJECTIVE
We evaluated a non-invasive ultrasound technique to assess early endothelial function in rabbits and compare data with ex vivo measurements.


METHODS
Twenty-four rabbits (fed with a cholesterol diet (0.5%) for 2 to 8 weeks) were given progressive infusions of acetylcholine (0.05-0.5 microg/kg/min) and their endothelial function was assessed in vivo by transcutaneous vascular ultrasound of the abdominal aorta. Ex vivo endothelial function was evaluated on isolated aortic rings and compared to in vivo data.


RESULTS
Significant endothelial dysfunction was demonstrated in hypercholesterolemic animals as early as 2 weeks after beginning the cholesterol diet (aortic cross-sectional area variation: -2.9% vs. +4% for controls, p < 0.05). Unexpectedly, response to acetylcholine at 8 weeks was more variable. Endothelial function improved in 5 rabbits while 2 rabbits regained a normal endothelial function. These data corroborated well with ex vivo results.


CONCLUSIONS
Endothelial function can be evaluated non-invasively in vivo by transcutaneous vascular ultrasound of the abdominal aorta in the rabbit and results correlate well with ex vivo data.
Groupe de recherche en valvulopathies, Institut de cardiologie de Québec, Centre de recherche Hôpital Laval, Université Laval, 2725 Chemin Sainte-Foy, Sainte-Foy, Canada. marie-claude.drolet@crhl.ulaval.ca
Marie-Claude
MC
Drolet
Eric
E
Plante
Bruno
B
Battistini
Jacques
J
Couet
Marie
M
Arsenault
D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D001018:Aortic Diseases / Q000139:chemically induced / Q000000981:diagnostic imaging*; D001161:Arteriosclerosis / Q000139:chemically induced / Q000000981:diagnostic imaging*; D002791:Cholesterol, Dietary; D004036:Diet, Atherogenic; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging*; D006937:Hypercholesterolemia / Q000139:chemically induced / Q000000981:diagnostic imaging*; D008297:Male; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography
D002791:Cholesterol, Dietary