Details

Autor(en) / Beteiligte

• Bourgoin, Frederic
• Bachelard, Helene
• Badeau, Mylene
• Melancon, Sebastien
• Pitre, Maryse
• Lariviere, Richard
• Nadeau, Andre

Titel

Endothelial and vascular dysfunctions and insulin resistance in rats fed a high-fat, high-sucrose diet

Ist Teil von

• American journal of physiology. Heart and circulatory physiology, 2008-09, Vol.295 (3), p.H1044-H1055

Ort / Verlag

United States: American Physiological Society

Erscheinungsjahr

2008

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• 1 Department of Medicine and Lipid Research Unit from Centre Hospitalier Université Laval (CHUL) Research Center, 2 Research Center of L'Hôtel Dieu de Québec, 3 Diabetes Research, Centre Hospitalier Universitaire de Québec (CHUQ), Laval University, Quebec, Canada Submitted 15 May 2008 ; accepted in final form 27 June 2008 This study was designed to examine the effects of a high-fat, high-sucrose (HFHS) diet on vascular and metabolic actions of insulin. Male rats were randomized to receive an HFHS or regular chow diet for 4 wk. In a first series of experiments, the rats had pulsed Doppler flow probes and intravascular catheters implanted to measure blood pressure, heart rate, and regional blood flows. Insulin sensitivity and vascular responses to insulin were assessed during a euglycemic hyperinsulinemic clamp performed in conscious rats. In a second series of experiments, new groups of rats were used to examine skeletal muscle glucose transport activity and to determine in vitro vascular reactivity, endothelial nitric oxide synthase (eNOS) protein expression in muscle and vascular tissues and endothelin content, nitrotyrosine formation, and NAD(P)H oxidase protein expression in vascular tissues. The HFHS-fed rats displayed insulin resistance, hyperinsulinemia, hypertriglyceridemia, hyperlipidemia, elevated blood pressure, and impaired insulin-mediated renal and skeletal muscle vasodilator responses. A reduction in endothelium-dependent vasorelaxation, accompanied by a decreased eNOS protein expression in muscles and blood vessel endothelium, and increased vascular endothelin-1 protein content were also noted in HFHS-fed rats compared with control rats. Furthermore, the HFHS diet induced a reduced insulin-stimulated glucose transport activity in muscles and increased levels of NAD(P)H oxidase protein and nitrotyrosine formation in vascular tissues. These findings support the importance of eNOS protein in linking metabolic and vascular disease and indicate the ability of a Westernized diet to induce endothelial dysfunction and to alter metabolic and vascular homeostasis. vascular endothelial function; oxidative stress Address for reprint requests and other correspondence: H. Bachelard, Lipid Research Unit, CHUL Research Center, CHUQ, 2705 blvd. Laurier, Ste-Foy, Quebec, Canada G1V 4G2 (e-mail: helene.bachelard{at}crchul.ulaval.ca )