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Biomedical subjects

T Fukazawa

Publications and source records attributed to T Fukazawa.

At least 181 records · Page 10Linked to original sources
PubMed1981

Effect of ATP concentration and pH on rigor tension development and dissociation of rigor complex in glycerinated rabbit psoas muscle fiber.

Isometric rigor tension development of glycerinated rabbit psoas muscle fibers in a medium, due to the formation of rigor complexes, was estimated at varying ATP concentrations from 0 to 2.5 mM and pH values from 6.75 to 8.20. The dissociation of rigor complexes was also estimated under the same conditions. When muscle fibers developed rigor tension from the relaxed and rigor states, the magnitude of rigor tension increased with increasing concentration of ATP. Transition between rigor and relaxation in single fibers occurred discontinuously at constant levels (critical levels) of ATP which were determined by pH. The critical concentrations of ATP necessary for inducing the transitions between rigor and relaxed states were also increased exponentially with increased pH. Incomplete repetition of tension development by the same fiber was also observed. This incomplete reversibility was divided into two types: one which showed a decay in rigor tension and another which showed no decay. The reason for the incomplete reversibility was discussed

Adenosine Triphosphate↗
PubMed1981

A new 220,000 dalton protein located in the Z lines of vertebrate skeletal muscle.

A new protein with a chain weight of approximately 220,000 was isolated from 0.6 M KI extracts of I-Z-I brushes of rabbit and chicken skeletal muscles, using (NH4)2SO4 precipitation and three column chromatographic procedures in succession. It was only possible to separate the high molecular weight protein from actin and alpha-actinin in the presence of 6 M urea or 0.1% sodium dodecyl sulfate (SDS). The purified protein migrated as a single band on SDS gel electrophoresis. The amino acid composition of the 220,000 dalton protein was distinct from any known proteins found in myofibrils, e.g., alpha-actinin and actin binding protein (ABP; filamin). An indirect immunofluorescence technique revealed that the new protein was exclusively located in the Z lines of myofibrils of chicken breast muscle. There is, however, a possibility that the 220,000 dalton protein is identical with synemin recently isolated from chicken gizzard (Granger, B.L. and Lazarides, E. (1980) Cell 22, 727).

Amino Acids↗
PubMed1980

Contributionof Z-line constituents to the formation of the contraction bands of chicken myofibrils on addition of Mg2+-ATP.

1. Z-line constituents contributing to the formation of the contraction bands in chicken myofibrils were investigated by using the rabbit calcium-activated factor (CAF). 2. CAF digestion hampered the formation of the contraction bands and increased the amount of soluble proteins which are apparently derived from the Z-line. Among several proteins released by CAF digestion, a 95,000 dalton component, which corresponds to alpha-actinin, was predominant, followed by a 220,000 dalton component and several other proteins. 3. An apparent inverse relationship between the formation of the contraction bands and the release of Z-line proteins was observed. It is concluded that the presence of Z-line, including at least the two components mentioned above, is essential for the formation of the contraction bands.

Actinin↗
PubMed1979

Clinicopathological study of soft tissue tumors.

Clinical aspects of patients with soft tissue tumors encountered at the Department of Orthopaedic Surgery, Toho University over a 15 year period between 1961 and 1976 were analyzed. Accurate clinical records and histological findings were available in 91 patients, 80 of whom had benign tumors and 11 of whom had malignant ones. Recurrence was seen in 7 of the 80 patients with benign tumors. The prognosis was poor in those with malignant tumors as expected, especially in those with rhabdomyosarcoma.

Adolescent↗
PubMed1978

Effect of calcium on extraction of Z-band proteins from I-Z-I brushes of rabbit striated muscle.

1. When rabbit striated muscle I-Z-I brushes were subjected to eleven extractions with three different extracting solutions, relatively more amount of proteins was extracted in the presence of 1 nM CaCl2 than in the presence of 5 mM EDTA or 5 mM ethyleneglycol-bisp(beta-aminoethylether)-N,N,N1,N1-tetra-acetic acid (EGTA). Among proteins extracted in the presence of 1 mM CaCl2, the protein components with molecular weights of 85,000, 95,000 and 220,000 were included, whereas these were not extracted in the other two. 2. Co-electrophoreses of 220,000 dalton protein and myosin heavy chain showed that these two protein components were distinct from each other. 3. Roles of Ca2+ are discussed on disintegration processes of I-Z-I brushes in special reference to its co-operative action with calcium-activated factor enzyme.

Animals↗
PubMed1978

Preparative study on the isolation of single sarcomeres from rabbit skeletal muscle.

Single sarcomeres were prepared from fresh rabbit myofibrils by digestion with a calcium-activated factor (CAF). The rabbit single sarcomere has functional properties quite similar to those of single sarcomeres obtained from chicken muscle by a usual method. Thus it was found that the single sarcomeres obtained by CAF digestion were useful as a muscle model, though they were not completely intact.

Actinin↗