Biomaterial Database

Effects of hydrostatic pressure on fatiguing frog muscle fibres. 1996

F Vawda, and K W Ranatunga, and M A Geeves

Department of Physiology, School of Medical Sciences, University of Bristol, UK.

Effects of increased hydrostatic pressure (range 0.1-10 MPa) on isometric twitch and tetanic contractions of single, intact, frog muscle fibres were examined at 4, 11 and 21 degrees C and at different stages of fatigue. Twitch tension was potentiated by pressure at all temperatures, but the extent of potentiation was more pronounced at higher temperatures (34% MPa-1 at 21 degrees C, compared to 8% MPa-1 at 4 degrees C). Tetanic tension was depressed by pressure at 4 degrees C (approximately 0.7% MPa-1) but was potentiated by pressure at 21 degrees C (approximately 0.4% MPa-1). The effect of hydrostatic pressure on the tetanic tension was dependent on the fatigue status of the muscle fibre: during the early stages of fatigue (when tetanic tension was depressed by < 20%), high pressure produced a tension depression (as in an unfatigued muscle fibre), whilst during the later stages of fatigue high pressure induced a significant potentiation of tetanic. Our results support the suggestion that excitation-contraction coupling and contractile activation are impaired during late fatigue. Pressure-effects were basically similar to caffeine-effects under a variety of conditions, suggesting that an enhancement of Ca2+ release may be contributory to potentiation of twitch tension and, in severely, fatigued muscle, potentiation of tetanic tension. In the rested state and during early fatigue the main effect of pressure is an inhibition of the crossbridge cycle.

UI	MeSH Term	Description	Entries
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D011896	Rana temporaria	A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.	European Common Frog,Frog, Common European,Common European Frog,Common Frog, European,European Frog, Common,Frog, European Common
D006874	Hydrostatic Pressure	The pressure due to the weight of fluid.	Hydrostatic Pressures,Pressure, Hydrostatic,Pressures, Hydrostatic
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
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D018482	Muscle, Skeletal	A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.	Anterior Tibial Muscle,Gastrocnemius Muscle,Muscle, Voluntary,Plantaris Muscle,Skeletal Muscle,Soleus Muscle,Muscle, Anterior Tibial,Muscle, Gastrocnemius,Muscle, Plantaris,Muscle, Soleus,Muscles, Skeletal,Muscles, Voluntary,Skeletal Muscles,Tibial Muscle, Anterior,Voluntary Muscle,Voluntary Muscles
D018485	Muscle Fibers, Skeletal	Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.	Myocytes, Skeletal,Myotubes,Skeletal Myocytes,Skeletal Muscle Fibers,Fiber, Skeletal Muscle,Fibers, Skeletal Muscle,Muscle Fiber, Skeletal,Myocyte, Skeletal,Myotube,Skeletal Muscle Fiber,Skeletal Myocyte
D018763	Muscle Fatigue	A state arrived at through prolonged and strong contraction of a muscle. Studies in athletes during prolonged submaximal exercise have shown that muscle fatigue increases in almost direct proportion to the rate of muscle glycogen depletion. Muscle fatigue in short-term maximal exercise is associated with oxygen lack and an increased level of blood and muscle lactic acid, and an accompanying increase in hydrogen-ion concentration in the exercised muscle.	Fatigue, Muscle,Muscular Fatigue,Fatigue, Muscular