The carnitine system and body composition

Abstract

Carnitine is a trimethylamine molecule that plays a unique role in cell energy metabolism. Mitochondrial betaoxidation of long-chain fatty acids, the major process by which fatty acids are oxidized, is ubiquitously dependent on carnitine. Control of mitochondrial beta-oxidation through carnitine adapts to differing requirements in different tissues. The physiological role of carnitine and its system in body composition is understood from insights into skeletal muscle metabolism, which converge into the metabolic heterogeneity of muscle fibers, and contractile properties that are correlated with phenotypes of resistance to fatigue. In skeletal muscle, the importance of the function of the carnitine system in the control and regulation of fuel partitioning not only relates to the metabolism of fatty acids and the capacity for fatty acid utilization, but also to systemic fat balance and insulin resistance. The carnitine system is shown to be determinant in insulin regulation of fat and glucose metabolic rate in skeletal muscle, this being critical in determining body composition and relevant raised levels of risk factors for cardiovascular disease, obesity, hypertension, and type 2 diabetes.

Vitamin C increases the fecal fat excretion by chitosan in guinea‐pigs, thereby reducing body weight gain

“…Chitosan may act as a bile acid-sequestering agent that reduces cholesterol by interrupting enterohepatic circulation (Parra-Barraza et al, 2005). Vitamin C is essential for the synthesis of muscle carnitine (Hulse et al, 1978), a small molecule responsible for shuttling long chain fatty acids across the mitochondrial membrane for β-oxidation, subsequent fat oxidation and energy production (Siliprandi et al, 1989;Reda et al, 2003). Thus, the vitamin C status may represent a modifi able condition that might impact the expression of the obesity phenotype (Johnston, 2005).…”

Effects of <smlcap>L</smlcap>-Carnitine on High Glucose-Induced Oxidative Stress in Retinal Ganglion Cells

“…The main functions of L -carnitine [3-hydroxy-4-(trimethylazaniumyl)butanoate] include transferring the long-chain fatty acids through the mitochondrial barrier, the protection of membrane structures and the reduction of lactate production [8]. Lipid metabolism disorder in ischemia and anoxia can lead to accumulation of fatty acyl-CoA, which in turn may lead to membrane structure damage and cell death [9,10]. In vitro studies have shown that L -carnitine as a free radical scavenger is an effective antioxidant [11,12].…”

Protein, glucose and lipid metabolism in the cancer cachexia: A preliminary report

“…These preliminary data could have a strong clinical impact, in fact based on them: 1) patients with cancer cachexia need close monitoring of parameters of the endocrine status and of energetic and nutritional homeostasis 2) these patients require a more aggressive nutritional management to prevent malnutrition (the use of amino acids integrator contain carnitine may be recommended) [13] and then improve the qualify of life in this patients seriously ill.…”