Search results for "Isolated mitochondria"
showing 5 items of 5 documents
Histochemistry of the Mitochondrial System
1964
It has been customary to introduce any discussion on the mitochondrion by summing up its functions as the energy center of the cell. Because of the extensive reviews and symposia in this field in recent years such an introduction would be repetitious and will therefore be omitted. — The relative ease by which mitochondria can be isolated from various cells and the considerable purity of such fractions permitted an analysis of the overall functions of mitochondria and the extrapolation of these results, on a statistical basis, to a single mitochondrion. Further fragmentation of isolated mitochondria into sub-units that carry segments of the functional activity of the whole organelle signific…
An Inhibitor of Cytochrome Oxidase Activity in the Sea Urchin Egg
1959
PREVIOUS work in this laboratory1,2 has demonstrated the presence of a highly active cytochrome oxidase in the isolated mitochondria of unfertilized sea urchin eggs. This activity is only 25 per cent lower than that of the mitochondria of the newly fertilized egg and up to the blastula stage2. No cytochrome oxidase activity has been found other than in the mitochondria1,3. On the other hand, it is known that the oxygen consumption of the unfertilized sea urchin egg is quite low; fertilization restores a normal respiratory level which increases continuously during the early development (for a discussion, see ref. 4). The suggestion was then made2 that in the unfertilized egg an extra-mitocho…
Mitochondria-related encephalomyopathies.
1989
Owing to advances in morphological and biochemical techniques, the mitochondria-related myopathies and encephalomyopathies have emerged as a still rapidly growing group of primary and secondary metabolic disorders, which may extend from infancy to late adulthood. Impairment of the biochemically diversified mitochondria is reflected in an enormous number of deficiencies, often affecting several mitochondrial enzymes in the same patient; morphologically abnormal mitochondria are common and are thus not specific to individual mitochondrial enzyme deficiencies. Skeletal muscle biopsies have provided a wealth of data through histological and histochemical studies and from isolated mitochondria. …
The cytochrome system in mitochondria of unfertilized sea urchin eggs
1958
Abstract 1. 1. The cytochrome system of unfertilized sea urchin eggs has been studied using preparations of isolated mitochondria. 2. 2. The difference spectra of isolated mitochondria show the presence of a complete and operating cytochrome system formed by the cytochromes a , a 3 , b and c . 3. 3. This cytochrome system is very similar to that of mammals and yeast as demonstrated by spectrophotometric and manometric experiments.
Dependence of hepatic gluconeogenesis on PO2: inhibitory effects of halothane
1987
The dependence of gluconeogenesis and O2 uptake on PO2 in isolated rat hepatocytes is presented. Maintenance of steady-state PO2 was achieved with an oxystat system (Biochem. J. 236: 765–769, 1986). O2 uptake showed a half-maximal (K0.5) value of 0.5 Torr PO2, whereas the glucose synthesis rate was half-maximal at 1.2 Torr PO2. Halothane at concentrations greater than 1 mM exerted a parallel inhibition of O2 uptake and glucose synthesis at all PO2 levels studied. In contrast, at halothane concentrations less than 1 mM, inhibition of glucose synthesis occurred only at less than 20 Torr PO2. At these low concentrations, halothane was without significant effects on cellular O2 uptake. In isol…