Biomaterial Database

Radial stiffness of frog skinned muscle fibers in relaxed and rigor conditions. 1984

Y Umazume, and N Kasuga

Radial stiffness in various conditions of mechanically skinned fibers of semitendinosus muscle of Rana catesbeiana was determined by compressing the fiber with polyvinylpyrrolidone (PVP K-30, Mr = 40,000) in incubating solution. The change in width (D) of fibers with increasing and decreasing PVP concentrations was highly reproducible at a range 0-6% PVP. Radial stiffness of relaxed fibers was almost independent of the sarcomere length. On the other hand, radial stiffness of rigor fibers showed a linear relation against the sarcomere length. These results indicate that cross-bridge attachment would be a major factor in the increase of the radial stiffness. Radial stiffness of relaxed and rigor fibers was (2.14 +/- 0.52) X 10(4) N/m2 (mean +/- SD) and (8.76 +/- 2.04) X 10(4) N/m2, respectively, at the relative fiber width (D/D0) of 0.92, where D0 denotes the fiber width in the rigor solution at 0% PVP. Radial stiffness of a fiber in a rigor solution containing pyrophosphate (PPi) was between those of relaxed and rigor fibers, i.e., (4.76 +/- 0.86) X 10(4) N/m2 at D/Do of 0.92. In PPi and rigor solutions, radial stiffness reversibly increased to around 150 and 130%, respectively, in the presence of 10(-6) M Ca2+. To explain these results, especially the Ca2+-induced change in the radial stiffness, some factor in addition to the number of attached cross-bridges has to be taken into account. The variation of radial stiffness under various conditions will be discussed in relation to the possible manner of cross-bridge attachment.

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
D009126	Muscle Relaxation	That phase of a muscle twitch during which a muscle returns to a resting position.	Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D011205	Povidone	A polyvinyl polymer of variable molecular weight; used as suspending and dispersing agent and vehicle for pharmaceuticals; also used as blood volume expander.	Polvidone,Polyvidon,Polyvinylpyrrolidone,Arufil,Bolinan,Bolinan 40,Crospovidone,Dulcilarmes,Duratears Free,Enterodes,Enterodez,Hypotears,Kollidon,Lacophtal,Lacri-Stulln,Lagrifilm,Liquifilm Lagrimas,Nutrivisc,Oculotect,PVP 40,Periston,Plasdone,Polyplasdone XL,Povidone, Unspecified,Protagens,Protagent,Unifluid,Vidirakt S mit PVP,Vidisic PVP Ophtiole,Wet-Comod,Dulcilarme,Enterode,Hypotear,Polyvidons,Protagen,Unspecified Povidone
D011892	Rana catesbeiana	A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.	Bullfrog,Bullfrogs,Rana catesbeianas,catesbeiana, Rana
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
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
D012518	Sarcomeres	The repeating contractile units of the MYOFIBRIL, delimited by Z bands along its length.	Sarcomere