Biomaterial Database

Exercise-induced alterations in skeletal muscle myosin heavy chain phenotype: dose-response relationship. 1999

H A Demirel, and S K Powers, and H Naito, and M Hughes, and J S Coombes

Department of Exercise and Sport Sciences and Physiology, Center for Exercise Science, University of Florida, Gainesville, Florida 32611, USA.

This study investigated the effects of exercise training duration on the myosin heavy chain (MHC) isoform distribution in rat locomotor muscles. Female Sprague-Dawley rats (120 days old) were assigned to either a sedentary control group or to one of three endurance exercise training groups. Trained animals ran on a treadmill at approximately 75% maximal O2 uptake for 10 wk (4-5 days/wk) at one of three different exercise durations (30, 60, or 90 min/day). Training resulted in increases (P < 0.05) in citrate synthase activity in the soleus and extensor digitorum longus in both the 60 and 90 min/day duration groups and in the plantaris (Pla) in all three exercise groups. All durations of training resulted in a reduction (P < 0.05) in the percentage of MHCIIb and an increase (P < 0.05) in the percentage of MHCIIa in the Pla. The magnitude of change in the percentage of MHCIIb in the Pla increased as a function of the training duration. In the extensor digitorum longus, 90 min of daily exercise promoted a decrease (P < 0.05) in percentage of MHCIIb and increases (P < 0.05) in the percentages of MHCI, MHCIIa, and MHCIId/x. Finally, training durations >/=60 min resulted in an increase (P < 0.05) in the percentage of MHCI and a concomitant decrease (P < 0.05) in the percentage of MHCIIa in the soleus. These results demonstrate that increasing the training duration elevates the magnitude of the fast-to-slow shift in MHC phenotype in rat hindlimb muscles.

UI	MeSH Term	Description	Entries
D009210	Myofibrils	The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .	Myofilaments,Myofibril,Myofilament
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D010805	Physical Conditioning, Animal	Diet modification and physical exercise to improve the ability of animals to perform physical activities.	Animal Physical Conditioning,Animal Physical Conditionings,Conditioning, Animal Physical,Conditionings, Animal Physical,Physical Conditionings, Animal
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
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
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D005082	Physical Exertion	Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.	Physical Effort,Effort, Physical,Efforts, Physical,Exertion, Physical,Exertions, Physical,Physical Efforts,Physical Exertions
D005260	Female		Females
D006207	Half-Life	The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.	Halflife,Half Life,Half-Lifes,Halflifes
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia