Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we will assume that you are happy to receive all cookies and you will not see this message again. Click 'Find out more' for information on how to change your cookie settings.

Cardiac utilisation of very-low-density lipoprotein (VLDL) and chylomicrons (CM) was investigated in the ZDF rat model of type 2 diabetes, in order to define the role of triacylglycerol (TAG) metabolism in the development of contractile dysfunction. Hearts from obese diabetic and lean littermate control rats were perfused with VLDL and CM from diabetic and control rats. Metabolic fate of the lipoprotein TAG and contractile function were examined. Myocardial utilisation of both VLDL- and CM-TAG was increased in the diabetic state. Diabetic hearts oxidised diabetic lipoprotein-TAG to a greater extent than control lipoproteins; glucose oxidation was decreased. There was no difference in lipoprotein-TAG assimilation into diabetic heart lipids; diabetic lipoproteins were, however, a poor substrate for control heart tissue lipid accumulation. Although the proportion of exogenous lipid incorporated into tissue TAG was increased in diabetic hearts perfused with control lipoproteins, this effect was not seen in diabetic hearts perfused with diabetic lipoproteins. Myocardial heparin-releasable lipoprotein lipase (LPL) activity was moderately increased in the diabetic state, and diabetic lipoproteins increased tissue-residual LPL activity. Cardiac hydraulic work was decreased only in diabetic hearts perfused with diabetic CM. Compositional analysis of diabetic variant lipoproteins indicated changes in size and apoprotein content. Alterations in cardiac TAG-rich lipoprotein metabolism in type 2 diabetes are due to changes in both the diabetic myocardium and the diabetic lipoprotein particle; decreased contractile function is not related to cardiac lipid accumulation from TAG-rich lipoproteins but may be associated with changes in TAG-fatty acid oxidation.

Original publication

DOI

10.1113/jphysiol.2009.173542

Type

Journal article

Journal

J Physiol

Publication Date

01/07/2009

Volume

587

Pages

3301 - 3315

Keywords

Animals, Chylomicrons, Diabetes Mellitus, Type 2, Energy Metabolism, Glucose, In Vitro Techniques, Lipoproteins, Lipoproteins, VLDL, Male, Myocardial Contraction, Myocardium, Obesity, Oxidation-Reduction, Perfusion, Rats, Rats, Zucker, Triglycerides