Dissociation of rat liver ribosomes by ethylenediaminetetraacetic acid; molecular weights, chemical composition, and buoyant densities of the subunits

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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A Comparison of Plasminogen Activators Derived from Rat Plasma, Primary Rat Hepatocytes and Isolated Perfused Rat Liver

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657155 ◽

1982 ◽

Vol 47 (02) ◽

pp. 166-172 ◽

Cited By ~ 4

Author(s):

Yoav Sharoni ◽

Maria C Topal ◽

Patricia R Tuttle ◽

Henry Berger

Keyword(s):

Rat Liver ◽

Isoelectric Point ◽

Rat Hepatocytes ◽

Cell Types ◽

Plasminogen Activators ◽

Rat Plasma ◽

Isolated Perfused Rat Liver ◽

Perfused Rat Liver ◽

Molecular Weights ◽

Physiological Relevance

SummaryOf the two cell types it was possible to culture from the dissociated rat liver, hepatocytes and Kupffer cells, only the former were fibrinolytically active. Rat hepatocytes during the first 24 hr in culture secreted two plasminogen activators with molecular weights identical to those found in rat plasma, an 80,000-dalton form (PA-80) and a 45,000-dalton form (PA-45). Partially purified preparations of plasminogen activators from both sources were subjected to isoelectric focusing (IEF) to compare characteristics further. There were three distinct peaks of PA-45 in each preparation with isoelectric points of 7.1, 7.2 and 7.4; all electrophoretic forms had the same low affinity to fibrin. PA-80 from both sources displayed similar IEF profiles with forms ranging from pH values of 7 to 8, all with the same high affinity to fibrin. The major form of PA-80 in the plasma preparation had an isoelectric point of 7.9 whereas that in the hepatocyte preparation had an isoelectric point of 7.6. The isolated perfused rat liver was also shown to produce both PA-80 and PA-45 emphasizing the physiological relevance of the findings with hepatocytes. It is concluded that in the rat hepatocytes contribute to the plasma profile with regard to the plasminogen activator content.

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Preparation of graft copolymers by the reaction of polymeric acyl chlorides with monohydroxy-terminated polymers: An introductory study

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19881735 ◽

1988 ◽

Vol 53 (8) ◽

pp. 1735-1744 ◽

Cited By ~ 1

Author(s):

Jitka Horská ◽

Jaroslav Stejskal ◽

Pavel Kratochvíl ◽

Aubrey D. Jenkins ◽

Eugenia Tsartolia ◽

...

Keyword(s):

Light Scattering ◽

Chemical Composition ◽

Statistical Model ◽

Graft Copolymers ◽

Coupling Reaction ◽

Molecular Characteristics ◽

Gel Formation ◽

Acyl Chlorides ◽

Molecular Weights

An attempt was made to prepare well-defined graft copolymers by the coupling reaction between acyl chloride groups located along the backbone chain and monohydroxy-terminated grafts prepared separately. The molecular weights and the parameters of heterogeneity in chemical composition of the products were determined by light scattering and osmometry. The determination of molecular characteristics revealed that the degree of grafting was low. The results therefore could not be confronted with a statistical model at this stage. The problems encountered in the synthesis, e.g., gel formation, and the data relating to the soluble products are discussed.

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Characterization and Partial Purification of Heterodisperse Polysomal RNAs in Normal and Neoplastic Cells

Tumori Journal ◽

10.1177/030089167205800203 ◽

1972 ◽

Vol 58 (2) ◽

pp. 71-94

Author(s):

Ada Sacchi ◽

Gianni Chinali ◽

Susetta Pons ◽

Michela Galdieri ◽

Piero Cammarano

Keyword(s):

Size Distribution ◽

Density Gradient ◽

Rat Liver ◽

Sucrose Density Gradient ◽

Partial Purification ◽

Messenger Rnas ◽

Alkaline Ph ◽

Sedimentation Profile ◽

Molecular Weights ◽

Phenol Extraction

The size distribution of cytoplasmic messenger RNAs (m-RNA) has been studied in rat liver and in monodifferentiated cells (mouse reticulocytes and myelomas). It has been found that the RNA which exhibits a « rapid turnover » and a polydisperse profile of radioactivity is refractory to phenol extraction. This property has been exploited to selectively isolate m–RNA from the phenol residue by means of an extraction at an alkaline pH. The sucrose density gradient profiles of m–RNA isolated from monodifferentiated cells show monodisperse peaks having the sedimentation coefficients expected on the basis of the molecular weights of monocistronic messages for α and β chains of hemoglobin (reticulocytes) and L and H chains of immunoglobulin (myelomas). The sedimentation profile of cytoplasmic m–RNA associated with rat liver polysomes shows a much broader distribution, with sedimentation coefficients ranging from 8 S to 28 S.

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