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J W HARMAN

Publications and source records attributed to J W HARMAN.

At least 19 recordsLinked to original sources
PubMed1955

Phase and electron microscope studies of the interrelationship of cytochondria and myofibrils in pigeon breast muscle.

MITOCHONDRIA IN PIGEON BREAST MUSCLE ARE COMPOSED OF TWO PROTEIN GELS: a fibrous gel, in the form of a folded ribbon, enclosed within a non-fibrous matrix. An external limiting "membrane" is not demonstrated, and there is poor demarcation between the mitochondria and adjacent structures or sarcoplasm. No internal structure has been determined for sarcosomes. These structures, however, are symplasmic with mitochondria and usually are located within mitochondrial depressions. They apparently have a high lipid content. The myofibrils also have no external limiting "membranes" and the mitochondria and sarcosomes are symplasmic with them. The mitochondria normally lie in the intermyofibrillar sarcoplasm oriented with their longitudinal axes parallel to the myofibrils. Cross-sections show that the myofilaments are oriented into well defined sheets.

Animals↗
PubMed1953

The cytological distribution in pigeon skeletal muscle of enzymes acting on phosphorylated nucleotides.

A procedure has been described for the centrifugal fractionation of the cytological components of pigeon breast muscle. An analysis of the distribution of enzyme activity among the different particles reveals a predominant location of magnesium-activated ATPase and myokinase in the cytochondria. The myofibrillar nuclear components are the site of calcium-activated ATPase and adenylic acid deaminase.

Animals↗
PubMed1953

The relationship between cytochondria and myofibrils in pigeon skeletal muscle.

In pigeon breast muscle the mitochondria are the principal site of oxidative metabolism, whereas the myofibrils are incapable of oxidizing intermediates of the Krebs cycle. The mitochondria contain the oxidative enzymes, and the sarcosomes are associated with a factor which accelerates the mitochondrial oxidative rate. The maintenance of myofibrillar contractility and structure is closely correlated with preservation of mitochondrial oxidative capacity and structure. By use of fluoride and dinitrophenol the connection between mitochondrial metabolism and myofibrillar behavior is shown to occur through the process of oxidative phosphorylation.

Animals↗