Lipid Metabolism in the Healthy and Disease Heart

The discovery of the second-messenger functions of on serine and threonine residues. Although there is inositol 1,4,5-trisphosphate (Ins(1 ,4,5)P 3) and 1,2-dia general agreement that PKC plays an important role in cylglycerol (DAG), the products of receptor-stimulated the initiation and/or modulation of receptor-linked re phosphatidylinositol 4,5-bisphosphate (PtdIns( 4,5)P ) 2 sponses, the precise nature or molecular details of this hydrolysis, marked a turning point in the studies on the involvement remain elusive. There are several sugges mechanisms of mediation of functional hormone and tions of possible functions of PKC, including involve neurotransmitter responses. The historical background ment in modulation of ionconductance, regulation of of this discovery and the extensive bibliography of the receptor interaction with components of (other) signal 2 enormously expanding knowledge in this field was re transduction pathways, modulation of Ca + sensitivity cently presented by Rana and Hokin [1], the latter of contractile proteins and gene expression [6]. author who first observed the 'phosphoinositide' effect The receptors involved in the activation of the adeny 35 years ago. It was, however, the Ca2+ gating hypothe late cyclase and PtdIns cascade pathways have one com sis proposed by Michell [2] on basis of a survey of mon feature. They are present in the plasmamembrane observations on the phosphoinositide turnover in a as complexes with GTP binding proteins (G-proteins).

Texte du rabat

The Third International Symposium on Lipid Metabolism in the Normoxic and Ischemic Heart was held in Rotterdam, the Netherlands, September 9-10, 1991. The topics of this meeting were focused on: 1. Modulation of myocardial lipid metabolism, 2. Biological membranes; structure, functiona and turnover, 3. Pharmacological modification of myocardial fatty acid oxidation, 4. Myocardial vascular endothelium; contribution to myocardial lipid homeostasis. Special attention is given to the interrelationship between carbohydrates and fatty acids as energy substrates for the heart under normoxic and (post) ischemic circumstances, the influence of diets, varying in their fatty acid composition, on cardiac function, and the significance of phospholipid topology, turnover, and methylation in general and the phosphatidylinositol pathway in particular on performance of the heart. The role of carnitine in cardiac function altered by lack of oxygen or by elevated levels of fatty acyl derivatives of carnitine and the modulatory effects of the endothelium on cardiac lipid homeostasis were also extensively discussed during the conference. This focused Issue of Molecular and Cellular Biochemistry is a collection of invited papers based on the lectures and a selection of posters presented during the meeting. It includes contributions of renowned investigators delineating recent results and discussing significant aspects of their data in an attempt to enlarge our insight in the complexity of cardiac lipid transport and metabolism, in the healthy and diseased myocardium.

Contenu
Paradoxical role of lipid metabolism in heart function and dysfunction.- Interrelationship between lactate and cardiac fatty acid metabolism.- Dietary modulation of lipid metabolism and mechanical performance of the heart.- The substrate specificity of phosphoinositide-phospholipase C in rat heart sarcolemma.- Long term incubation of cardiac myocytes with oleic acid and very-low density lipoprotein reduces heparin-releasable lipoprotein lipase activity.- Carnitine palmitoyltransferase in the heart is controlled by a different mechanism than the hepatic enzyme.- Myocardial cell vulnerability to exogenous phospholipase attack.- Phosphatidylcholine metabolism in ischemic and hypoxic hearts.- Occurrence and functions of the phosphatidylinositol cycle in the myocardium.- Modulation of phosphatidylethanolamine biosynthesis by exogenous ethanolamine and analogues in the hamster heart.- Eicosapentaenoic and docosahexaenoic cultured rat ventricular myocytes and hypoxia-induced alterations of phospholipase-A activity.- Incorporation of radioiodinated fatty acids into cardiac phospholipids of normoxic canine myocardium.- Kinetic changes of ethanolamine base exchange activity and increase of viscosity in sarcolemmal membranes of hamster heart during development of cardiomyopathy.- Annexins in cardiac tissue: cellular localization and effect on phospholipase activity.- Myocardial fatty acid oxidation during ischemia and reperfusion.- The relative contribution of glucose and fatty acids to ATP production in hearts reperfused following ischemia.- Effects of palmitoyl CoA and palmitoyl carnitine on the membrane potential and Mg2{+} content of rat heart mitochondria.- Carnitine requirement of vascular endothelial and smooth muscle cells in imminent ischemia.- Protection of the ischemicdiabetic heart by L-propionylcarnitine therapy.- Functional and metabolic effects of propionyl-L-carnitine in the isolated perfused hypertrophied rat heart.- L- propionylcarnitine and myocardial performance in stunned porcine myocardium.- Release of heart fatty acid-binding protein into plasma after acute myocardial infarction in man.- Regulatory functions of the coronary endothelium.- Lipid metabolism of myocardial endothelial cells.- Endothelium, the dynamic interface in cardiac lipid transport.- Malondialdehyde is a biochemical marker of peroxidative damage in the isolated reperfused rat heart.- Studies on the interaction of leucocytes and the myocardial vasculature. I. Effect of hypoxia on the adherence of blood granulocytes.- Arachidonic acid incorporation in cardiomyocytes, endothelial cells and fibroblast-like cells isolated from adult rat heart.