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  • Rat  (40)
  • Springer  (40)
  • American Chemical Society
  • 1985-1989  (26)
  • 1980-1984  (14)
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Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 34 (1982), S. 376-381 
    ISSN: 1432-0827
    Keywords: Matrix vesicles ; Bone ; Actin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Preliminary indications of the occurrence of actin and myosin in crude matrix vesicle preparations have been reported previously. In the present study extracellular matrix vesicles from rat alveolar bone were isolated. They were further purified by a sucrose density gradient. SDS-polyacrylamide gel electrophoresis of the purified vesicles revealed the presence of a polypeptide with a molecular weight of 43 K daltons and with electrophoretic mobility identical to that of blood platelet actin. The limited proteolysis of both 43 K dalton vesicular polypeptide and actin byStaphylococcus aureus-V8-protease revealed three fragments with identical electrophoretic mobility. In addition, the vesicular preparations inhibited the activity of DNase I, a property typical of actin monomers. Filamentous material extracted from matrix vesicles showed ultrastructural features of F-actin. Reaction of this material with heavy meromyosin resulted in arrowhead formation, which is characteristic of acto-heavy meromyosin. The occurrence of actin in extracellular matrix vesicles may account for their budding from the osteoblastic plasma membrane, their possible motility in the matrix, and maintenance of the spherical shape.
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  • 2
    ISSN: 1573-9104
    Keywords: Soybean ; Rapeseed ; Wheat ; Protein fractions ; Protein efficiency ratio ; Digestibility ; Vegetable protein blends ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Blends of vegetable proteins were prepared to improve the nutritive value of these proteins. Soybean flour, rapeseed protein concentrate, whole wheat flour, soybean 2S+11S extract, wheat albumin-globulin + glutenin (AG+G) functions, and some of their blends were compared to casein for protein efficiency ratio (PER) and apparent digestibility coefficient (ADC). Autoclaving (1 h) soybean proteins was also studied. Casein and rapeseed protein concentrate gave the highest weight gains and PER. Other protein sources gave lower values for both PER (P〈0.05) and weight gain. The digestibility of all vegetable proteins was lower (P〈0.05) than that of casein. PER of soybean 2S+11S extract was significantly lower (P〈0.05) than that of soybean flour. Autoclaving significantly (P〈0.05) improved the PER of both soybean flour and 2S+11S extract. The ADC of autoclaved 2S+11S extract was similar (P〈0.05) to that of autoclaved soybean flour and significantly higher (P〈0.05) than that of 2S+11S extract. Soybean flour had the lowest (P〈0.05) ADC. Heat treatment destroyed antinutritional factors, probably trypsin inhibitors and/or haemagglutinins of soybean. This was accompanied by improvement in the nutritional value of protein. The four blends were chosen on the basis of amino acid composition, chromatography of proteolyzates and nutritive value of each fraction. The PER of wheat albumin-globulin and glutenin (AG+G) blend was similar (P〈0.05) to that of wheat flour and lower (P〈0.05) than that of all other blends used. Wheat AG+G+rapeseed protein concentrate and wheat AG+G+soybean flour blends gave the highest (P〈0.05) PER. Wheat AG+G improved the PER of 2S+11S extract and of soybean flour but decreased the PER of rapeseed protein concentrate. Wheat AG+G and wheat AG+G+rapeseed protein concentrate blends gave an ADC significantly higher (P〈0.05) than that of wheat AG+G blend containing soybean flour of 2S+11S extract. However, blending wheat AG+G with either 2S+11S extract of soybean flour improved ADC.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 239 (1985), S. 229-233 
    ISSN: 1432-0878
    Keywords: Chemotherapy ; Vincristine ; Constipation ; Mucosa ; Regulatory peptides ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The microtubule-disrupting drug vincristine is a common component of anti-cancer chemotherapeutic regimes, which produces acute constipation as a side effect. Although generally attributed to damage to the myenteric plexus, the precise mechanism of this disturbance is unknown. In addition, vincristine causes marked aberrations in the secretory response of pancreatic endocrine tissue in both man and rats. No information is available on its possible effect on regulatory peptides of the gastrointestinal tract. In this study we have produced vincristine-induced constipation in rats at a dosage comparable with that employed in the treatment of human subjects. Immunocytochemistry revealed concomitant disturbances in cells exhibiting immunoreactivity for gastrin in the antrum, for gastric inhibitory polypeptide and 5-hydroxytryptamine in the duodenum, for enteroglucagon in the colon, and for somatostatin in all three sites. These widespread effects are transient in nature with normal cell numbers and morphology being reestablished within 6 days. It is suggested that the observed effects are a direct result of microtubule disruption and that gastrointestinal regulatory peptide and amine immunoreactive cells have a rapid regeneration potential.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 211 (1980), S. 175-177 
    ISSN: 1432-0878
    Keywords: Parietal cell ; Stomach ; Circadian rhythm ; Morphometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gastric parietal cells of rats maintained under standardized conditions and fed ad libitum were examined by electron microscopy at 6 time points of the 24-h day. Morphometric determinations were made on 4 cell characteristics. The volume density of secretory canaliculi was maximal at the mid-dark sampling point and decreased during the light phase; a secondary peak was seen 1 h before the onset of darkness. The surface density of microvesicles and RER fluctuated inversely with the pattern displayed by secretory canaliculi. The number of multivesicular bodies per cytoplasmic area exhibited a single peak, 1 h after the onset of darkness. It was further noted that parietal cells in the necks and bases of glands differed morphologically and that their organelle populations varied at individual circadian rates.
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  • 5
    ISSN: 1432-0878
    Keywords: AVT ; LHRH ; α-MSH ; Somatostatin ; Pineal Gland ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Resumé En utilisant des anticorps contre l'AVT, l'α-MSH, le LHRH et la somatostatine, des cellules épiphysaires du Rat ont été immunocytochimiquement colorées. Tous ces anticorps colorent les mêmes cellules. Ces cellules réagissent également quand un anticorps est utilisé contre la fraction épiphysaire UMO5R, fraction qui est douée de propriétés antigonadotropiques in vivo. Il a également été montré que le nombre des cellules immunoréactives était plus important dans la pinéale du jeune rat que dans celle de l'adulte. La comparaison des résultats obtenus avec différents anticorps et l'étude des propriétés de ces anticorps aprés absorption sur différents peptides ou sur différentes fractions épiphysaires, a permis de conclure que les réactions obtenues dans la pinéale du rat n'étaient que la conséquence d'une réaction croisée de ces anticorps avec une/des substance(s) inconnue(s) synthétisée(s) par la pinéale elle-même. La nature endocrine possible de cette substance qui serait chimiquement apparenté aux fractions épiphysaires Mouton UMO5R et Prot. 4, est discutée. Drs. B.L. Baker (Ann Arbor, Mich., USA), M.P. Dubois (Nouzilly, France), J. De Mey (Beerse, Belgium), J.D. Fernstrom (Cambridge, Mass., USA.), H. Goos (Utrecht, The Netherlands), B. Kerdelhué (Gif-sur-Yvette, France) and A.G.E. Pearse (London, U.K.) are also acknowledged for their gifts of various antibodies
    Notes: Summary Using antibodies against AVT, α-MSH, LHRH and somatostatin, immunoreactive cells were detected in the rat pineal gland. All of these antibodies stain the same cells, which also react immunocytochemically when an antibody against the UMO5R sheep pineal fraction, a fraction that presents antigonadotropic properties in vivo, is used. Relatively more immunoreactive cells are present in the pineals of young rats than in the pineals of adult animals. Comparison of the results obtained with different potent antibodies against each of the peptides, and a study of the staining properties of the antibodies in the pineal after solid phase adsorption to different peptides or to different sheep pineal fractions, led to the proposal that the immunoreactivity found in the rat pineal is not due to the presence of AVT, α-MSH, LHRH or somatostatin, but to a cross-reaction of each of these antibodies with (an) unidentified compound(s). This compound is synthetized in the pineal gland, as was demonstrated using cultured pineals. The UMO5R and the Prot. 4 fractions of the sheep pineal seem to be chemically related to this unknown compound, the possible endocrine nature of which is discussed.
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  • 6
    ISSN: 1432-0878
    Keywords: Splenic implants ; Non-lymphoid cells ; Trapping ; Enzyme histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Regeneration of splenic tissue after autologous subcutaneous implantation provides a useful model for studying the development of splenic tissue. The development of the various non-lymphoid cells of the white pulp in the rat is described. It appears that regeneration of the implants is initiated by ingrowing vessels and a newly formed reticulum, which forms the microenvironment for the homing lymphocytes. Marginal metallophils are found at their characteristic location at the inner border of the marginal sinus five weeks after implantation. Trapping of antigen-antibody complexes reappears when the first primary follicles can be recognized.
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  • 7
    ISSN: 1432-0878
    Keywords: Splenic implants ; Immunoperoxidase technique ; Lymphocyte homing ; Interdigitating cells ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The localization of T-and B lymphocytes and interdigitating cells (IDC) was investigated during the regeneration process of splenic implants. For this purpose a two-step immunoperoxidase technique was used to visualize T-cell antigen, immunoglobulins and Ia-antigen on cryostat sections. The specific localization of the repopulating lymphocytes occurred simultaneously with the development of non-lymphoid elements characteristic for the different compartments of the white pulp, i.e., the periarteriolar lymphocyte sheaths (PALS) and follicles. The marginal zone (MZ) developed after the PALS and primary follicles, but before germinal center reactions were found. During ontogeny, however, the development of a broad MZ precedes the formation of follicles. This difference in sequence of events is discussed.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 228 (1983), S. 451-457 
    ISSN: 1432-0878
    Keywords: Bone matrix vesicles ; Parathyroid hormone ; Mineralization ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The enzymatic activity of bone matrix vesicles from parathyroidectomized rats was determined and compared to the activity of vesicles from sham operated and normal animals. The vesicles were isolated from the alveolar bone by collagenase digestion and differential centrifugation and further purified on a discontinuous sucrose density gradient. The amount of extractable protein and the activity of alkaline phosphatase, acid phosphatase, and ATPase in the vesicle fractions thus obtained did not differ significantly from the values characteristic of preparations from control rats. It may therefore be suggested that parathyroid hormone depletion and the associated hypocalcemia have no significant effect on the occurrence and phosphatase activity of bone matrix vesicles.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 247 (1987), S. 179-185 
    ISSN: 1432-0878
    Keywords: Image analysis ; Morphometry ; Peroxisomes ; Catalase ; Cytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The feasibility of the application of a television-based image analyzer, the Texture Analysis System (TAS, Leitz Wetzlar, FRG) in conjunction with a light microscope for morphometric studies of hepatic peroxisomes has been investigated. Rat liver peroxisomes were stained with the alkaline-DAB method for localization of catalase and semi-thin (0.25 and 1 μm) sections of plastic-embedded material were examined under an oil immersion objective. The TAS detected the peroxisomal profiles selectively and determined their morphometric parameters automatically. The same parameters were obtained also by morphometric analysis of electron micrographs from the same material. The volume density of peroxisomes determined by TAS in semithin sections of normal liver, after correction for section thickness, is quite close to the corresponding value obtained by morphometry of electron micrographs. The difference is approximately 20%. In animals treated with the hypolipidemic drug bezafibrate, which causes proliferation of peroxisomes, TAS detected readily the increase in volume density of peroxisomes in semithin sections. In comparison with electron microscopy, however, the light-microscopic approach seems to underestimate the proliferation. The lower resolution of the light microscope and overlapping of neighbouring particles in relatively thick sections used for lightmicroscopic analysis may account for the differences. The present study has demonstrated the usefulness of automatic image analysis in conjunction with selective cytochemical staining of peroxisomes for morphometry of this organelle in rat liver. The light-microscopic approach is not only faster but is also extremely economical by obviating the use of an electron microscope.
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  • 10
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Proteinase inhibitor ; Feedback regulation ; Cholecystokinin ; Fine structure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Application of a single dose of a new type of proteinase inhibitor camostate (FOY-305) via orogastric tube was used in rats to study the dose-response relationship of resulting pancreatic stimulation. Doses up to 10 mg/ kg failed to elicit any response, while significant decrease in enzyme content and increase in serum CCK-levels were observed with doses ranging from 25 to 400 mg/kg. A single dose of 100 mg/kg was selected for a time-sequence analysis, which revealed a 60 to 70% depletion of enzyme stores persisting over 6 h and reverting to control levels by 12 h. Peak increases in serum CCK-levels (15-fold above the elevation observed after regular food intake) were found after 30 min and persisted as an 8-to 10-fold elevation for at least 3 h, then declined to control levels by 9 h. This prolonged endogenous hormone release and resulting pancreatic stimulation were also verified in a separate group of animals in which volume, protein, and enzyme output were measured after cannulation of the pancreatic duct. While volume secretion was not altered by feeding a single dose of 100 mg/kg FOY-305, protein and enzyme output increased 2-to 3-fold over a period of 7 h. Fine-structural analysis of the pancreas demonstrated efficient depletion of zymogen granules from acinar cells with all doses between 50 and 400 mg/kg, accompanied by the appearance of membrane material in the acinar lumina at 3 and 6 h. The same transient increase in the number of lysosomal bodies predominantly containing mitochondria with all doses above 50 mg/kg was interpreted as increased organelle turnover due to persisting hormonal stimulation.
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