Cardiac function and lipid distribution in rats fed a high-fat diet: in vivo magnetic resonance imaging and spectroscopy.
Obesity is a major risk factor in the development of cardiovascular disease, type 2 diabetes, and its pathophysiological precondition insulin resistance. Very little is known about the metabolic changes that occur in the myocardium and consequent changes in cardiac function that are associated with high-fat accumulation. Therefore, cardiac function and metabolism were evaluated in control rats and those fed a high-fat diet, using magnetic resonance imaging, magnetic resonance spectroscopy, mRNA analysis, histology, and plasma biochemistry. Analysis of blood plasma from rats fed the high-fat diet showed that they were insulin resistant (P < 0.001). Our high-fat diet model had higher heart weight (P = 0.005) and also increasing trend in septal wall thickness (P = 0.07) compared with control diet rats. Our results from biochemistry, magnetic resonance imaging, and mRNA analysis confirmed that rats on the high-fat diet had moderate diabetes along with mild cardiac hypertrophy. The magnetic resonance spectroscopy results showed the extramyocellular lipid signal only in the spectra from high-fat diet rats, which was absent in the control diet rats. The intramyocellular lipids in high-fat diet rats was higher (8.7%) compared with rats on the control diet (6.1%). This was confirmed by electron microscope and light microscopy studies. Our results indicate that lipid accumulation in the myocardium might be an early indication of the cardiovascular pathophysiology associated with type 2 diabetes.
['Nagarajan|Vijayasarathi|V|', 'Gopalan|Venkatesh|V|', 'Kaneko|Manami|M|', 'Angeli|Veronique|V|', 'Gluckman|Peter|P|', 'Richards|Arthur Mark|AM|', 'Kuchel|Philip W|PW|', 'Velan|S Sendhil|SS|']
D000818:Animals D001391:Azo Compounds D001786:Blood Glucose D001835:Body Weight D006332:Cardiomegaly D004396:Coloring Agents D059305:Diet, High-Fat D004435:Eating D006321:Heart D007333:Insulin Resistance D050356:Lipid Metabolism D008279:Magnetic Resonance Imaging D009682:Magnetic Resonance Spectroscopy D008297:Male D008855:Microscopy, Electron, Scanning D009206:Myocardium D009765:Obesity D012333:RNA, Messenger D051381:Rats D011916:Rats, Inbred F344 D060888:Real-Time Polymerase Chain Reaction D014280:Triglycerides
cardiac function EMCL IMCL cardiac metabolism