Biomaterial Database

Long- and medium-chain fatty acid oxidation is increased in exercise-trained human skeletal muscle. 2002

Kim Jong-Yeon, and Robert C Hickner, and G Lynis Dohm, and Joseph A Houmard

Department of Biochemistry, Diabetes/Obesity Center, East Carolina University, Greenville, NC 27858, USA.

The purpose of this study was to test the hypothesis that skeletal muscle fatty acid oxidation is enhanced by increased entry into the mitochondria with exercise training. Muscle was obtained from young ( approximately 24 years) sedentary (n = 13) and endurance-trained (n = 10) volunteers and oxidation studied by measuring (14)CO(2) production from labeled medium-chain (MCFA) or long-chain (LCFA) fatty acids in muscle homogenate preparations. LCFA (palmitate) oxidation was (P <.05) approximately 34% higher in the trained than sedentary subjects (26.9 +/- 3.0 v 17.8 +/- 1.3 nmol CO(2)/g x h). MCFA (octanoate) oxidation was also about 26% higher (P <.05) in the trained subjects (21.7 +/- 2.1 v 16.1 +/- 2.0 nmol CO(2)/g x h). To examine the roles of carnitine-mediated transport and mitochondrial content, we also measured carnitine palmitoyltransferase I (CPT1), carnitine octanoyl transferase (COT), and citrate synthase (CS) activities. CPT1 and CS activity were significantly (P <.05) higher (approximately 25%) in the endurance-trained subjects; there was no difference in COT activity. These data suggest that adaptations at the level of CPT1 and processes distal to this step may contribute to increases in LCFA or MFCA oxidation with exercise training. In contrast, carnitine-mediated transport (COT) does not appear to contribute to an enhancement in MCFA oxidation with exercise training.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D012044	Regression Analysis	Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.	Regression Diagnostics,Statistical Regression,Analysis, Regression,Analyses, Regression,Diagnostics, Regression,Regression Analyses,Regression, Statistical,Regressions, Statistical,Statistical Regressions
D002210	Caprylates	Derivatives of caprylic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a carboxy terminated eight carbon aliphatic structure.	Caprylate,Octanoates,Caprylic Acids,Octanoic Acids,Acids, Caprylic,Acids, Octanoic
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D002331	Carnitine	A constituent of STRIATED MUSCLE and LIVER. It is an amino acid derivative and an essential cofactor for fatty acid metabolism.	Bicarnesine,L-Carnitine,Levocarnitine,Vitamin BT,L Carnitine
D002333	Carnitine Acyltransferases	Acyltransferases in the inner mitochondrial membrane that catalyze the reversible transfer of acyl groups from acyl-CoA to L-carnitine and thereby mediate the transport of activated fatty acids through that membrane. EC 2.3.1.	Acylcarnitine Translocase,Carnitine Translocase,Carnitine-Acetylcarnitine Translocase,Carnitine-Acylcarnitine Translocase,Acyltransferases, Carnitine,Carnitine Acetylcarnitine Translocase,Carnitine Acylcarnitine Translocase,Translocase, Acylcarnitine,Translocase, Carnitine,Translocase, Carnitine-Acetylcarnitine,Translocase, Carnitine-Acylcarnitine
D002334	Carnitine O-Palmitoyltransferase	An enzyme that catalyzes reversibly the conversion of palmitoyl-CoA to palmitoylcarnitine in the inner mitochondrial membrane. EC 2.3.1.21.	Carnitine Palmitoyltransferase,CPT II,Carnitine Acyltransferase I,Carnitine Palmitoyltransferase I,Carnitine Palmitoyltransferase II,Palmitoylcarnitine Transferase,Palmitylcarnitine Acyltransferase,Acyltransferase I, Carnitine,Acyltransferase, Palmitylcarnitine,Carnitine O Palmitoyltransferase,II, Carnitine Palmitoyltransferase,O-Palmitoyltransferase, Carnitine,Palmitoyltransferase I, Carnitine,Palmitoyltransferase II, Carnitine,Palmitoyltransferase, Carnitine,Transferase, Palmitoylcarnitine
D002950	Citrate (si)-Synthase	Enzyme that catalyzes the first step of the tricarboxylic acid cycle (CITRIC ACID CYCLE). It catalyzes the reaction of oxaloacetate and acetyl CoA to form citrate and coenzyme A. This enzyme was formerly listed as EC 4.1.3.7.	Citrate Synthase,Synthase, Citrate
D005230	Fatty Acids, Nonesterified	FATTY ACIDS found in the plasma that are complexed with SERUM ALBUMIN for transport. These fatty acids are not in glycerol ester form.	Fatty Acids, Free,Free Fatty Acid,Free Fatty Acids,NEFA,Acid, Free Fatty,Acids, Free Fatty,Acids, Nonesterified Fatty,Fatty Acid, Free,Nonesterified Fatty Acids