DNA-nucleotidyl transferase activity in supernatant and membrane fractions from normal and regenerating rat liver mitochondria

1. A method was devised to allow determination of intramitochondrial aspartate amino-transferase activity in suspensions of intact mitochondria. 2. Addition of purified rat liver mitochondrial aspartate aminotransferase to suspensions of rat liver mitochondria caused an apparent increase in the intramitochondrial enzyme activity. No increase was observed when the mitochondria were preincubated with the purified cytoplasmic isoenzyme. 3. These results suggest that mitochondrial aspartate aminotransferase, but not the cytoplasmic isoenzyme, is able to pass from solution into the matrix of intact rat liver mitochondria in vitro. 4. This system may provide a model for studies of the little-understood processes by which cytoplasmically synthesized components are incorporated into mitochondria in vivo.

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Studies on the glutathione S-transferase activity associated with rat liver mitochondria

Biochemical Journal ◽

10.1042/bj2220553 ◽

1984 ◽

Vol 222 (2) ◽

pp. 553-556 ◽

Cited By ~ 6

Author(s):

C M Ryle ◽

T J Mantle

Keyword(s):

Lactate Dehydrogenase ◽

Rat Liver ◽

Liver Mitochondria ◽

Rat Liver Mitochondria ◽

Transferase Activity ◽

Marker Enzymes ◽

Glutathione S Transferase ◽

Mitochondrial Marker ◽

Liver Glutathione

The major proportion of rat liver glutathione S-transferase is cytosolic. Carefully washed mitochondria contain 0.25-0.47% of the cytosolic activity. Subfractionation of washed mitochondria using digitonin treatment revealed that glutathione S-transferase release did not parallel that of any of the mitochondrial marker enzymes. Glutathione S-transferase release paralleled that of lactate dehydrogenase, suggesting that these ‘mitochondrial’ activities are due to loosely bound cytoplasmic forms.

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Characterization of rat liver mitochondria depleted of inner membrane components by chloramphenicol treatment of regenerating rat liver

Archives of Biochemistry and Biophysics ◽

10.1016/0003-9861(76)90115-6 ◽

1976 ◽

Vol 172 (2) ◽

pp. 611-617 ◽

Cited By ~ 6

Author(s):

Robert J. Fisher

Keyword(s):

Rat Liver ◽

Liver Mitochondria ◽

Rat Liver Mitochondria ◽

Inner Membrane ◽

Regenerating Rat Liver ◽

Membrane Components

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Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066917 ◽

1971 ◽

Vol 29 ◽

pp. 570-571

Author(s):

E. A. Elfont ◽

R. B. Tobin ◽

D. G. Colton ◽

M. A. Mehlman

Keyword(s):

Chemical Composition ◽

Rat Liver ◽

Future Study ◽

Mode Of Action ◽

Liver Mitochondria ◽

Rat Liver Mitochondria ◽

Effective Inhibitor ◽

Biochemical Effects ◽

Glycerophosphate Dehydrogenase ◽

Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

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