Formation, isolation and composition of dense granules from mitochondria

Weinbach, Eugene C.; Brand, Theodor von

doi:10.1016/0304-4165(67)90301-7

Cited by 51 publications

(31 citation statements)

References 19 publications

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“…(The preparation still gave a continuous ring, electron-diffraction pattern of hydroxyapatite, but it was slightly grainy by comparison to that from the 600°C-heated material.) erated granules of 16-60 % depending on the preparation (Weinbach and von Brand, 1967). The present microincineration results are also consistent with this picture.…”

supporting

confidence: 91%

Microincineration, Electron Microscopy, and Electron Diffraction of Calcium Phosphate-Loaded Mitochondria

Thomas

Greenawalt

1968

The Journal of Cell Biology

106

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Isolated rat liver mitochondria were incubated in vitro under conditions supporting the massive accumulation of calcium and phosphate. Samples were embedded, thin sectioned, and examined in the electron microscope. The intramitochondrial distribution of insoluble or structure-bound mineral substances was studied by electron microscopy coupled with recently developed techniques of high resolution microincineration. As shown previously, the ion-loaded mitochondria acquire large, internal granules which have inherent electron opacity indicative of high mineral content. Study of ash patterns in preselected areas of sections directly confirmed the high mineral content of the granules, and the appearance of the residues was consistent with the copresence in the granules of some organic material. Other mitochondrial structures were almost devoid of mineral. Thin sections of unincubated control mitochondria also were incinerated. They were found to contain appreciable amounts of intrinsic mineral, seemingly associated with membranes. The normal, dense matrix granules commonly seen in unaltered mitochondria could be seen in intact sections of these control preparations, but after burning no definite correspondence of any ash to the granules could be demonstrated. The normal granules perhaps do not contain mineral. Heating experiments on ash patterns of all the preparations demonstrated the thermal stability and crystallizability of the ash. The crystallized ash of the in vitro-produced dense granules was tentatively shown by electron diffraction to be 3-tricalcium phosphate (whitlockite). This, together with evidence from the literature, suggests that the original, noncrystalline mineral may be a colloidal, subcrystalline precursor of calcium-deficient hydroxyapatite. Experiments were performed on synthetic calcium phosphates for comparison. Other possible applications of the microincineration techniques are briefly discussed.

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confidence: 91%

Microincineration, Electron Microscopy, and Electron Diffraction of Calcium Phosphate-Loaded Mitochondria

Thomas

Greenawalt

1968

The Journal of Cell Biology

106

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“…Without the uptake of ATP (or ADP), no granules were formed (5). Weinbach and Von Brandt then found that the granules contained adenine nucleotides (28). The possible co-precipitation of Ca-P i and nucleotide was, therefore, a potential explanation of why ATP accelerated mitochondrial Ca 2ϩ uptake.…”

Section: Discussionmentioning

confidence: 99%

Dual Effect of Phosphate Transport on Mitochondrial Ca2+ Dynamics

Wei

Liu

O’Rourke

2015

Journal of Biological Chemistry

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“…Matrix granules as described by Peachey (1969) and Weinbach andVon Brand (1965, 1967) were considered to be accumulation spots of calcium, their major function being the regulation of ion concentrations. But, on the contrary, Somlyo et al (1977Somlyo et al ( , 1985 have shown that, under physiologic conditions, NMG apparently played no role in Ca homeostasis.…”

Section: Composition Of Nmgmentioning

confidence: 99%

Mitochondrial matrix granules: Their behavior during changing metabolic situations and their relationship to contact sites between inner and outer mitochondrial membranes

Jacob

Hertsens

Biermans

1994

Microscopy Res & Technique

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Since their discovery in the early fifties mitochondrial granules have been the subject of many researches. Some twenty years ago two hypotheses on their function were introduced. Peachey thought that the granules were a sink of cations and that they would eventually regulate the concentrations of these ions. Alternatively, Barnard thought that the granules were precursors of the mitochondrial inner membrane. There are only a few data on organic constituents of the granules. Phospholipids (e.g., cardiolipin) glycoprotein or lipids, calcium precipitable lipoprotein, cytochrome c oxidase seem to be present in the granules. There has been much debate on whether calcium is present or not. Reports are mostly based on X-ray microanalysis, the result of which depends on preparation techniques. In heart muscle in stimulating situations the NMG (native matrix granules) move towards the inner membrane and are incorporated in it. They appear to create contact sites between inner and outer mitochondrial membranes in which enzymes can function efficiently. It is hypothetized that the system, NMG-contact sites, forms the structural basis of a regulatory mechanism, by which cells can cope with a high and sudden energy demand.

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Formation, isolation and composition of dense granules from mitochondria

Cited by 51 publications

References 19 publications

Microincineration, Electron Microscopy, and Electron Diffraction of Calcium Phosphate-Loaded Mitochondria

Microincineration, Electron Microscopy, and Electron Diffraction of Calcium Phosphate-Loaded Mitochondria

Dual Effect of Phosphate Transport on Mitochondrial Ca2+ Dynamics

Mitochondrial matrix granules: Their behavior during changing metabolic situations and their relationship to contact sites between inner and outer mitochondrial membranes

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