Atypical Electron Microscope Structures in Liver Mitochondria

Pathobiology ◽  
1973 ◽  
Vol 39 (2) ◽  
pp. 112-114 ◽  
Author(s):  
E. Valdivia ◽  
J.E. Berger
Keyword(s):  
Electron Microscope ◽  
Liver Mitochondria

scholarly journals DEVELOPMENT OF AN IMPROVED MEDIUM FOR THE ISOLATION OF LIVER MITOCHONDRIA

1956 ◽  
Vol 2 (5) ◽  
pp. 609-624 ◽  
Author(s):  
M. S. C. Birbeck ◽  
E. Reid
Keyword(s):  
Adverse Effect ◽  
Molecular Weight ◽  
Electron Microscope ◽  
Acid Phosphatase ◽  
Mitochondrial Fraction ◽  
Liver Mitochondria ◽  
High Concentration ◽  
Mitochondrial Fractions ◽  
Sucrose Medium ◽  
Optimal Medium

In view of the unsatisfactory appearance, under the electron microscope, of liver mitochondria isolated in isotonic sucrose medium, alternative media have been examined. It was found to be advantageous to replace sucrose by raffinose, and to add levan or, preferably, dextran, together with heparin in suitable concentration. With the optimal medium, the constituents of which are raffinose, versene (optional), dextran of high molecular weight, heparin, and AMP (optional), most of the mitochondria in the osmium-fixed pellet are apparently intact, and show the membranes characteristic of mitochondria as seen in cell sections. The optimal medium has no adverse effect on the activity of the several tissue enzymes which have been studied, except that Mg++-activated ATPase is partially inhibited if the medium is present in high concentration in the assay system. Mitochondrial fractions isolated in the new medium have, in common with sucrose fractions, appreciable "free" ATPase activity, this activity being evidently a poor criterion of mitochondrial integrity. Use of the new medium does not decrease the proportion of cytoplasmic ATPase which fails to sediment with the mitochondria, but does give a mitochondrial fraction low in RNA and in acid phosphatase activity and little contaminated with microsomal material. Particles tentatively identified as "lysosomes" have been seen in certain sections.

scholarly journals MORPHOLOGY AND ATP-ASE OF ISOLATED MITOCHONDRIA

1955 ◽  
Vol 1 (2) ◽  
pp. 127-138 ◽  
Author(s):  
Robert F. Witter ◽  
Michael L. Watson ◽  
Mary A. Cottone
Keyword(s):  
Electron Microscope ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Substantial Part ◽  
Mitochondrial Matrix ◽  
Isolated Mitochondria ◽  
The Matrix ◽  
First Time ◽  
Methods Of Isolation

Changes in the morphology of rat liver mitochondria brought about by different methods of isolation and the concomitant changes in ATP-ase activity were studied. The morphology was investigated with the electron microscope. It was found that the ATP-ase activity of the isolated mitochondria cannot be readily correlated with the morphology of the mitochondria. The ATP-ase found in these preparations was latent, resembling the enzyme described in mitochondria prepared in 0.25 M sucrose. In confirmation of earlier results the use of 0.88 M sucrose yielded preparations with a higher initial ATP-ase than did other methods. Preparation in 0.25 M sucrose resulted in round, swollen mitochondria of which 30 to 40 per cent appeared to have lost a substantial part of the mitochondrial matrix. Preparations in 0.44 to 0.88 M sucrose contained mainly rod-shaped mitochondria plus a small amount of another type of swollen mitochondria. The matrix of mitochondria isolated in 0.88 M sucrose was highly condensed. By the use of 0.44 M sucrose adjusted to pH 6.2 with citric acid, it was possible to isolate, for the first time, mitochondria closely resembling those in situ and containing latent ATP-ase.

scholarly journals Cholesterol increase in mitochondria: its effect on inner-membrane functions, submitochondrial localization and ultrastructural morphology

1993 ◽  
Vol 289 (3) ◽  
pp. 703-708 ◽  
Author(s):  
S Echegoyen ◽  
E B Oliva ◽  
J Sepulveda ◽  
J C Díaz-Zagoya ◽  
M T Espinosa-García ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Atpase Activity ◽  
Succinate Dehydrogenase ◽  
Outer Membrane ◽  
Rat Liver ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Inner Membrane ◽  
Ultrastructural Morphology ◽  
Mitochondrial Inner Membrane

The effect of cholesterol incorporation on some functions of the mitochondrial inner membrane and on the morphology of rat liver mitochondria was studied. Basal ATPase and succinate dehydrogenase activities remained unchanged after cholesterol was incorporated into the mitochondria; however, uncoupled ATPase activity was partially inhibited. The presence of several substrates and inhibitors did not change the amount of cholesterol incorporated, which was localized mostly in the outer membrane. Electron-microscope observations revealed the presence of vesicles between the outer and inner membranes; these vesicles increased in number with the amount of cholesterol incorporated. The data suggest that cholesterol induces the formation of vesicles from the outer membrane, and modifies the activity of stimulated ATPase.

scholarly journals THE MORPHOLOGY OF THE SWELLING PROCESS IN RAT LIVER MITOCHONDRIA

1971 ◽  
Vol 48 (2) ◽  
pp. 291-302 ◽  
Author(s):  
D. R. Myron ◽  
J. L. Connelly
Keyword(s):  
Electron Microscope ◽  
Outer Membrane ◽  
Rat Liver ◽  
Conformational Changes ◽  
Large Amplitude ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
The Matrix

Through the use of combined spectrophotometric and electron microscope techniques, large amplitude swelling of rat liver mitochondria has been described as an ordered sequence of ultrastructural transitions. Prior to the actual swelling, mitochondria undergo two major conformational changes: condensed to twisted form and twisted to orthodox form. This sequence is independent of (a) the nature of swelling agents and (b) the time of onset of swelling. Agents that delay the onset of swelling act to increase the duration of the twisted conformation. Agents that prevent extensive swelling hold mitochondria in intermediate conformations. Gross swelling, immediately preceded by a decrease in electron opacity of the matrix, involves the rupture of the outer membrane and expansion of the inner compartment of the mitochondrion.

Mode of effect of Ostruthin, a phenolic coumarin on respiration and oxidative phosphorylation of rat liver mitochondria

1980 ◽  
Vol 45 (2) ◽  
pp. 653-664 ◽  
Author(s):  
Vladimír Dadák ◽  
Petr Zbořil ◽  
Josef Šanek ◽  
Augustin Svoboda
Keyword(s):  
Electron Microscope ◽  
Monoamine Oxidase ◽  
Mitochondrial Membrane ◽  
Respiratory Control ◽  
Liver Mitochondria ◽  
Mitochondrial Proteins ◽  
Phosphorus Compounds ◽  
Rat Liver Mitochondria ◽  
Outer Mitochondrial Membrane ◽  
Freeze Etching

Ostruthin (6-genaryl-7-hydroxycoumarin) in concentration of 5-30 nmol/mg protein behaves as an uncoupler. It eliminates the respiratory control in liver mitochondria, decreases the ratioof ADP/O uptake, and stimulates ATPase activity. It also acts as an inhibitor of the exchange reaction between 32Pi and ATP. Higher concentrations induce the swelling of mitochondria, bring about changes in the permeability of the membrane, and significantly alter the ultrastructure of mitochondria. A considerable quantity of mitochondrial proteins and a part of the phosphorus compounds are released into solution during this process. The investigation of the distribution of typical enzymes of membranes and matrix (monoamine oxidase, cytochrome oxidase, succinate dehydrogenase, and malate dehydrogenase) has shown that the mitochondrial components released come from matrix. Ostruthin concentrations higher than 50 nmol/mg protein cause fragmentation of membranes observable in ultrathin slices in the electron microscope. Fragmentation of both the inner and the outer mitochondrial membrane was demonstrated by the method of freeze etching.

scholarly journals PREVENTION OF PHOSPHATE - INDUCED MITOCHONDRIAL SWELLING

1962 ◽  
Vol 15 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Arnold J. Kroll ◽  
Toichiro Kuwabara
Keyword(s):  
Electron Microscope ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Liver Mitochondria ◽  
Mitochondrial Swelling ◽  
Rat Liver Mitochondria ◽  
Isolated Rat Liver ◽  
Isolated Rat

The prevention of phosphate-induced mitochondrial swelling in the whole retina of the rabbit was studied with the electron microscope. It was found that a mixture of ATP, Mg++, and bovine serum albumin protected the mitochondria in vitro. This finding confirmed the results obtained spectrophotometrically with isolated rat liver mitochondria by Lehninger.

Electron Cytochemical Study of Carbon Dioxide Laser Effect on Rhesus Monkey Cornea

1974 ◽  
Vol 32 ◽  
pp. 224-225
Author(s):  
K. C. Tsou ◽  
J. Morris ◽  
P. Shawaluk ◽  
B. Stuck ◽  
E. Beatrice
Keyword(s):  
Carbon Dioxide ◽  
Electron Microscope ◽  
Rhesus Monkey ◽  
Carbon Dioxide Laser ◽  
Cytochemical Study ◽  
Laser Effect

While much is known regarding the effect of lasers on the retina, little study has been done on the effect of lasers on cornea, because of the limitation of the size of the material. Using a combination of electron microscope and several newly developed cytochemical methods, the effect of laser can now be studied on eye for the purpose of correlating functional and morphological damage. The present paper illustrates such study with CO2 laser on Rhesus monkey.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Utilizing Dark Field Electron Microscopy to Produce Lantern Slides

1974 ◽  
Vol 32 ◽  
pp. 116-117
Author(s):  
J. N. Meador ◽  
C. N. Sun ◽  
H. J. White
Keyword(s):  
Electron Microscope ◽  
Electron Micrographs ◽  
Dark Field ◽  
Limiting Factor ◽  
Clinical Laboratories ◽  
Field Electron ◽  
Time Element ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Dark Field Micrographs

The electron microscope is being utilized more and more in clinical laboratories for pathologic diagnosis. One of the major problems in the utilization of the electron microscope for diagnostic purposes is the time element involved. Recent experimentation with rapid embedding has shown that this long phase of the process can be greatly shortened. In rush cases the making of projection slides can be eliminated by taking dark field electron micrographs which show up as a positive ready for use. The major limiting factor for use of dark field micrographs is resolution. However, for conference purposes electron micrographs are usually taken at 2.500X to 8.000X. At these low magnifications the resolution obtained is quite acceptable.

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