In vivo sup 31 P-NMR spectroscopy of chronically stimulated canine skeletal muscle

Journal Article · Mon Feb 01 00:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6870113

Clark, III, B J; McCully, A K; Subramanian, H V; Hammond, R L; Salmons, S; Chance, B; Stephenson, L W ^[1]

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1. Children's Hospital of Philadelphia, Harrison (USA) Univ. of Pennsylvania School of Medicine, Philadelphia (USA) Univ. of Birmingham (England)

Chronic stimulation converts skeletal muscle of mixed fiber type to a uniform muscle made up of type I, fatigue-resistant fibers. Here, the bioenergetic correlates of fatigue resistance in conditioned canine latissimus dorsi are assessed with in vivo phosphorus-31 nuclear magnetic resonance ({sup 31}P-NMR) spectroscopy. After chronic electrical stimulation, five dogs underwent {sup 31}P-NMR spectroscopic and isometric tension measurements on conditioned and contralateral control muscle during stimulation for 200, 300, 500, and 800 ms of an 1,100-ms duty cycle. With stimulation, phosphocreatine (PCr) fell proportional to the degree of stimulation in both conditioned and control muscle but fell significantly less in conditioned muscle at all the least intense stimulation period (200 ms). Isometric tension, expressed as a tension time index per gram muscle, was significantly greater in the conditioned muscle at the two longest stimulation periods. The overall small change in PCr and the lack of a plateau in tension observed in the conditioned muscle are similar to that seen in cardiac muscle during increased energy demand. This study indicates that the conditioned muscle's markedly enhanced resistance to fatigue is in part the result of its increased capacity for oxidative phosphorylation.

• OSTI ID: 6870113
• Journal Information: American Journal of Physiology; (USA), Vol. 254:2; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
EXERCISE
PHYSIOLOGY
MUSCLES
NUCLEAR MAGNETIC RESONANCE
ATP-ASE
BEAGLES
BIOELECTRICITY
BIOLOGICAL FATIGUE
BIOLOGICAL RECOVERY
ELECTROPHORESIS
ERYTHROCYTES
OXIDATION
PHOSPHORUS 31
PHOSPHORYLATION
STIMULATION
ACID ANHYDRASES
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CHEMICAL REACTIONS
DOGS
ELECTRICITY
ENZYMES
HYDROLASES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MAMMALS
MATERIALS
NUCLEI
ODD-EVEN NUCLEI
PHOSPHOHYDROLASES
PHOSPHORUS ISOTOPES
RECOVERY
RESONANCE
STABLE ISOTOPES
VERTEBRATES
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