Very-low-density lipoprotein: complex particles in cardiac energy metabolism.

The heart is a major consumer of energy and is able to utilise a wide range of substrates including lipids. Nonesterified fatty acids (NEFA) were thought to be a favoured carbon source, but their quantitative contribution is limited because of their relative histotoxicity. Circulating triacylglycerols (TAGs) in the form of chylomicrons (CMs) and very-low-density lipoprotein (VLDL) are an alternative source of fatty acids and are now believed to be important in cardiac metabolism.

Myocardial metabolism of triacylglycerol-rich lipoproteins in type 2 diabetes.

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.

Metabolism of very-low-density lipoprotein and chylomicrons by streptozotocin-induced diabetic rat heart: effects of diabetes and lipoprotein preference.

Very-low-density lipoprotein (VLDL) and chylomicrons (CM) are major sources of fatty acid supply to the heart, but little is known about their metabolism in diabetic myocardium. To investigate this, working hearts isolated from control rats and diabetic rats 2 wk following streptozotocin (STZ) injection were perfused with control and diabetic lipoproteins. Analysis of the diabetic lipoproteins showed that both VLDL and CM were altered compared with control lipoproteins; both were smaller and had different apolipoprotein composition.

Utilization of triacylglycerol-rich lipoproteins by the working rat heart: routes of uptake and metabolic fates.

Very-low-density lipoprotein (VLDL) and chylomicrons (CMs) transport triacylglycerol (TAG) to peripheral tissues. Lipoprotein-TAG may gain access to target cells by lipoprotein lipase (LPL) hydrolysis or via receptor-mediated uptake; the principal routes of entry of VLDL and CM into heart are unknown, and different routes of entry may result in different metabolic fates. To examine this, isolated working rat hearts were perfused with rat VLDL and CMs, dual-labelled with [3H]TAG and [14C]cholesterol.

[Recent advances in multi-variate and multi-dimensional analysis of heart rate variability and blood pressure variability].

Heart rate variability (HRV) and blood pressure variability (BPV) reflect the modulation activity of autonomic nervous system on cardiovascular function. There have been important advances in multi-variate, multi-dimensional and dynamic analysis of HRV and BPV during recent years. Modern signal processing methods, such as multi-variate system identification, time-frequency analysis and nonlinear dynamics analysis, could be adopted in the risk prediction, severity evaluation and therapeutic treatment assessment of cardiovascular diseases.