ABSTRACT
mTOR enzyme belongs to a family of specific serine/threonine protein kinases. mTOR plays an important role in the transmission of extracellular signals by phosphorylation of various substrates in many metabolic reactions in humans. Protein mTOR, having protein kinase activity, is encoded by a gene FRAP1, which is localized on chromosome 1 (1p36.2) in skeletal muscle. It exists in two mTOR protein complexes mTORC1 and mTORC2 with various sensitivity to the inhibitory effect of rapamycin. mTOR regulates metabolism in skeletal muscle by phosphorylation of various of protein metabolizing enzymes as well as transcription and translation factors. mTOR expression occurs in response to metabolic requests of muscles and leads to increased metabolism of proteins. The data of recent studies suggest an important role of mTOR in the regulation of intracellular metabolism and point to the need of studying the molecular mechanisms involved in physiological function of skeletal muscles.
Subject(s)
Muscle, Skeletal/metabolism , Signal Transduction , TOR Serine-Threonine Kinases/metabolism , Humans , Mechanistic Target of Rapamycin Complex 1 , Mechanistic Target of Rapamycin Complex 2 , Multiprotein Complexes/metabolism , Muscle, Skeletal/physiology , Phosphorylation , Protein Biosynthesis/genetics , Sirolimus/metabolismABSTRACT
Aerobic training led to enhancement of lipase activity in type IIA type muscles. Still more obvious changes were found in rats trained to aerobic swimming with maximal intensity. In latter activity, a rise of the fatty acid-binding protein (FABP) was revealed in types I and IIA skeletal muscles. These adaptive changes led to enhancement of lipid metabolism. It was also shown that the FABP content decreased after physical exercise more obviously in the trained animals due, probably, to their substance turnover enhancement.
Subject(s)
Fatty Acids/metabolism , Lipase/metabolism , Muscle, Skeletal/metabolism , Neoplasm Proteins , Nerve Tissue Proteins , Physical Conditioning, Animal , Physical Endurance , Adaptation, Physiological , Animals , Biological Transport , Carrier Proteins/metabolism , Fatty Acid-Binding Protein 7 , Fatty Acid-Binding Proteins , Glycogen/metabolism , Liver/metabolism , Muscle Fibers, Skeletal/metabolism , Muscle, Skeletal/enzymology , Muscle, Skeletal/ultrastructure , RatsABSTRACT
Lipase activity was studied in preparations of skeletal muscles and fatty tissue by means of measurement of oleic acid methyl ester concentration developed after triolein hydrolysis using gas-liquid chromatography apparatus. The procedure described helped unify the methodology approaches in estimation of tissue lipases activity and of free fatty acid spectrum of blood serum in microquantities of the material studied, it exhibited high sensitivity and specificity.