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  • 1
    Electronic Resource
    Electronic Resource
    Experimentally induced colon cancer metastases in rat liver increase the proliferation rate and capacity for purine catabolism in liver cells (1993)
    Springer
    Histochemistry and cell biology 100 (1993), S. 41-51 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Metastases in rat liver were generated experimentally by intraportal injection of colon cancer cells to investigate the effects of cancerous growth on the metabolism of surrounding liver tissue. Maximum activities (capacity) of glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, lactate dehydrogenase, succinate dehydrogenase, alkaline phosphatase, 5′-nucleotidase, xanthine oxidoreductase, purine nucleoside phosphorylase and adenosine triphosphatase have been determined. Two types of metastases were found, a small type surrounded by stroma and a larger type in direct contact with hepatocytes. Both types affected the adjacent tissue in a similar way suggesting that the interactions were not mediated by stroma. High capacity of the degradation pathway of extracellular purines released from dead cells of either tumours or host tissue was found in stroma and sinusoidal cells. Metastases induced both an increase in the number of Kupffer cells and proliferation of hepatocytes. The distribution pattern in the liver lobulus of most enzymes investigated did not change distinctly. However, activity of alkaline phosphatase, succinate dehydrogenase and phosphogluconate dehydrogenase was increased in hepatocytes directly surrounding metastases. These data imply that the overall metabolic zonation in liver lobuli is not dramatically disturbed by the presence of cancer cells despite the fact that various metabolic processes in liver cells are affected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00268877
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  • 2
    Electronic Resource
    Electronic Resource
    Kupffer cells and pit cells are not effective in the defense against experimentally induced colon carcinoma metastasis in rat liver (1996)
    Springer
    Clinical & experimental metastasis 14 (1996), S. 367-380 
    Details
    ISSN: 1573-7276
    Keywords: colon cancer ; Kupffer cells ; liver ; metastasis ; pit cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: The present study was performed to investigate processes involved in circumvention of the immune system by advanced stages of tumor growth in the liver. The efficacy of Kupffer cells and pit cells against cancer cells was tested in vivo in an experimental model of colon carcinoma metastasis in rat liver. Liver tumors were induced by administration of CC531 colon cancer cells into the vena portae. After 3 weeks, livers were obtained and partly fixed for electron microscopic procedures or frozen in liquid nitrogen for enzyme and immunohistochemistry at the light microscope level. The activation status of Kupffer cells was studied by expression of la-antigen (MHC class II) and by measurement of glucose-6-phosphate dehydrogenase (G6PDH) activity in the cells in situ as a measure of production of reactive oxygen species. Large numbers of Kupffer cells were found in liver parenchyma surrounding colon carcinomas when compared with levels in control livers, but these cells were not activated. Large numbers of activated monocytes and macrophages, cytotoxic T cells but only a few pit cells were found to be recruited to the boundary between liver parenchyma and tumors or their stroma. In those areas where cancer cells invaded liver parenchyma, only newly recruited macrophages and some Kupffer cells were present but few cytotoxic T cells or pit cells were found. The low activation status of Kupffer cells both in terms of production of reactive oxygen species and Ia-antigen expression and the absence of significant numbers of pit cells at tumor sites suggest that Kupffer cells and pit cells do not play a significant role in advanced stages of tumor growth. High levels of prostaglandin E2 were detected in the parenchyma of livers containing tumors and transforming growth factor β was detected in the stroma of the tumors, therefore suggest that cytotoxicity of newly recruited monocytes, macrophages and cytotoxic T cells may be limited in these stages because of local production of these immunosuppressive factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00123396
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  • 3
    Electronic Resource
    Electronic Resource
    Localization of cathepsin B activity in fibroblasts and chondrocytes by continuous monitoring of the formation of a final fluorescent reaction product using 5-nitrosalicylaldehyde (1987)
    Springer
    Journal of molecular histology 19 (1987), S. 483-487 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The histochemical fluorescence method using 5-nitrosalicylaldehyde for the demonstration of cathepsin B activity has been used. Precipitation of the fluorescent final reaction product was analysed continuously during incubation for cathepsin B activity. Unfixed cultured human fibroblasts as well as cryostat sections of mouse metacarpal bone explants were used. Continuous monitoring of the formation of the fluorescent reaction product showed that after a certain lag phase, depending on the enzyme activity in the tissue, discrete granules appeared which became increasingly fluorescent with incubation time. Subsequently, recrystallization and redistribution of the final reaction product started to occur. It is concluded that the coupling reaction with 5-nitrosalicylaldehyde is sufficiently fast for a proper localization of proteinase activity and can be used for ‘kinetic’ analysis of enzyme activity. The method provides indications of relative amounts of cathepsin B activity in different cell types within a tissue section. It appeared from the study on metacarpal bone explants that fibroblasts in perichondrium and periosteum contained a relatively high cathepsin B activity whereas chondrocytes showed a low but distinct activity. This observation suggests that cysteine proteinases are not only involved in collagen degradation by fibroblasts but that they also play a role in the intracellular digestion of collagen by chondrocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01675418
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  • 4
    Electronic Resource
    Electronic Resource
    Cytophotometric analysis of reaction rates of succinate and lactate dehydrogenase activity in rat liver, heart muscle and tracheal epithelium (1989)
    Springer
    Journal of molecular histology 21 (1989), S. 575-583 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Reaction rates of succinate and lactate dehydrogenase activity in cryostat sections of rat liver, tracheal epithelium and heart muscle were monitored by continuous measurement of formazan formation by cytophotometry at room temperature. Incubation media contained polyvinyl alcohol as tissue protectant and Tetranitro BT as final electron acceptor. Control media lacked either substrate or substrate and coenzyme. Controls were also performed by adding malonate (a competitive inhibitor of succinate dehydrogenase), pyruvate (a non-competitive inhibitor of lactate dehydrogenase), oxalate (a competitive inhibitor of lactate dehydrogenase) orN-ethylmaleimide (a blocker of SH groups). A specific malonate-sensitive linear test minus control response for succinate dehydrogenase activity was obtained in liver (1.6 µmol H2 cm−3min−1) and tracheal epithelium (0.8 µmol H2cm−3 min−1) but not in heart muscle. All variations in the incubation conditions tested did not result in a linear test minus control response in the latter tissue. Because the reaction was sensitive to malonate, it was concluded that the initial reaction rate was the specific rate of succinate dehydrogenase activity in heart muscle (9.1 µmol H2 cm−3 min−1). Test minus control reactions for lactate dehydrogenase activity were distinctly non-linear for all tissues tested. This appeared to be due to product inhibition by pyruvate generated during the reaction and therefore it was concluded that the appropriate control reaction was the test reaction in the presence of 20mm pyruvate. The initial rate of the test minus this control was the true rate of lactate dehydrogenase activity. The lactate dehydrogenase activity thus found in liver parenchyma was 5.0 µmol of H2 generated per cm3 liver tissue per min.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01753358
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  • 5
    Electronic Resource
    Electronic Resource
    In situ detection of spontaneous superoxide anion and singlet oxygen production by mitochondria in rat liver and small intestine (1997)
    Springer
    Journal of molecular histology 29 (1997), S. 229-237 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In the present study, the endogenous formation of reactive oxygen species was localized in rat liver and small intestine. The 3,3′-diaminobenzidine (DAB)-Mn2+ technique in which cobalt ions were included in the incubation medium was applied to unfixed cryostat sections of intact tissues. Addition of manganese ions to the DAB-Co2+- containing medium greatly increased the amounts of final reaction product formed compared with incubations with only DAB and cobalt ions. In liver, a blue final reaction product was deposited, particularly in hepatocytes surrounding portal tracts. In the small intestine, the DAB--cobalt complex was mainly found at the basal side of enterocytes. Goblet cells remained unstained. Electron microscopical images revealed that an electron-dense reaction product was exclusively present at both inner and outer membranes and at the intermem brane space in mitochondria of liver parenchymal cells and duodenal enterocyt es. It was shown that the spontaneous formation of final reaction product was enzymatic and dependent on the presence of oxygen in the medium. Sulphide decreased the reaction, which may indicate that cytochrome c oxidase was partiall y involved. Benzoquinone and histidine, which are scavengers of superoxide anions and singlet oxygen respectively, reduced the amount of final reaction product considerably. Furthermore, the formation of final reaction product was sensitive to specific inhibitors of NADH:coenzy me Q reductase and aldehyde oxidase, indicating that these enzymes were at least partly responsible for the generation of superoxide anions and singlet oxygen and for the formation of the DAB--cobalt complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026453926517
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  • 6
    Electronic Resource
    Electronic Resource
    Cytophotometry of glucose-6-phosphate dehydrogenase activity in individual cells (1983)
    Springer
    Journal of molecular histology 15 (1983), S. 583-599 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary With the aid of thin films of polyacrylamide gel containing purified glucose-6-phosphate dehydrogenase subjected to cytochemical procedures for the enzyme using tetranitro blue tetrazolium, arbitrary units of integrated absorbance obtained with a Barr & Stroud GN5 cytophotometer were converted into units of enzyme activity. This conversion enabled cytochemical data to be compared directly with biochemical values. The conversion was applied to the cytochemical estimation of glucose-6-phosphate dehydrogenase activity in isolated rat hepatocytes, mouse oocytes, rabbit thymocytes, human granulocytes and human fibroblasts. Several control procedures were performed to confirm the admissibility of this conversion, such as: the estimation of the absorption characteristics of the formazans of tetranitro blue tetrazolium both in solution and precipitated in biological specimens; the linearity of the relationship between the increase of absorbance and incubation time; and the effect of different incubation conditions on the amount of specific formazan production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01954149
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  • 7
    Electronic Resource
    Electronic Resource
    On the nature of the ‘nothing dehydrogenase’ reaction (1985)
    Springer
    Journal of molecular histology 17 (1985), S. 1111-1118 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The biochemical mechanism underlying the ‘nothing dehydrogenase’ reaction during the histochemical demonstration of dehydrogenases using tetranitro BT as the final electron acceptor has been investigated in unfixed, frozen rat liver sections. The reaction is stronger with NAD+ than either with NADP+ or in the absence of coenzyme. As much as 50% of the reaction is due to lactate dehydrogenase converting endogenous lactate and is largely inhibited by pyruvate. No NAD+-dependent alcohol dehydrogenase activity was detected at pH 7.45, the pH used for the incubations. The coenzyme-independent activity may be caused by SH-groups present in proteins and compounds like glutathione and cysteine and can be inhibited byN-ethylmaleimide andp-chloromercuribenzoic acid. It was also found that the ‘nothing dehydrogenase’ reaction mainly occurs during the first few minutes of incubation, levelling off quickly to a slow rate. When studying the kinetics of dehydrogenase reactions with tetrazolium salts, it should be realized that the ‘nothing dehydrogenase’ reaction, which as a whole is nonlinear with time, can interfere seriously with the dehydrogenase reaction to be analysed and may yield initial reaction rates that are too high. The findings of the present study reveal the nature of the reactions used for detection of necrosis in tissues with tetrazolium salts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01002536
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  • 8
    Electronic Resource
    Electronic Resource
    Plasma ornithine carbamyl transferase level as an indicator of ischaemic injury of rat liver (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Cell Biochemistry and Function 2 (1984), S. 217-220 
    Details
    ISSN: 0263-6484
    Keywords: Liver ; OCT ; ischaemia ; necrosis ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The activity of ornithine carbamyl transferase (OCT) and glutamate pyruvate transaminase (GPT) in serum has been correlated with the extent of necrosis 24 h after different periods of ischaemia in rat liver. The extent of necrosis has been quantified as the volume density of necrosis in the total ischaemic liver lobes using tetranitro BT. The GPT-activity in serum is maximal between 1 and 5 h after different periods of ischaemia, whereas OCT reaches its maximum between 5 and 12 h after ischaemia. The total amount of leaked enzyme-activity as well as the peak value give a linear correlation with the extent of necrosis for OCT and GPT. There is a differnece between the character of these two enzymes in that a small leakage of GPT does not indicate liver cell necrosis later on. However, the appearance of OCT in the blood, an enzyme localized in the mitochondrial matrix, has a predictive value for the extent of necrosis, likely to occur later on. GPT, an enzyme from the cytoplasm, can also occur in the blood during the reversible stage of liver cell damage.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cbf.290020407
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  • 9
    Electronic Resource
    Electronic Resource
    Cytophotometric analysis of alkaline phosphatase and 5′-nucleotidase activity in regenerating rat liver after partial hepatectomy (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Cell Biochemistry and Function 6 (1988), S. 53-60 
    Details
    ISSN: 0263-6484
    Keywords: Partial hepatectomy ; regenerating liver ; alkaline phosphatase ; 5′-nucleotidase ; histochemistry ; cytophotometry ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Alkaline phosphatase and 5′-nucleotidase activities were analysed cytophotometrically in cryostat sections of female rat liver after partial hepatectomy. Alkaline phosphatase activity increased rapidly after operation up to a maximum seven-fold rise at 24 h in comparison with sham operated or control rats. There was no indication of preferential localization of alkaline phosphatase activity in either periportal or pericentral areas at any time point in control rats, sham operated rats or hepatectomized rats. Microscopical observation revealed that (a) all alkaline phosphatase activity was present at the bile canalicular surface of hepatocytes and (b) hepatocytes in mitosis did not show any increase in activity. These findings indicate that the high alkaline phosphatase activity after partial hepatectomy is not involved primarily in proliferation processes because cell division mainly takes place periportally. It may be needed for enhanced bile secretion by conversion of intracellular phosphorylcholine into choline which can be transported into the bile. The intracellular phosphorylcholine level is high after operation due to changes in phospholipid metabolism. 5′-Nucleotidase appeared to be three times higher pericentrally than periportally under normal conditions. Partial hepatectomy caused a 40 per cent decrease in activity in pericentral areas and only a small decrease periportally. It has been suggested that 5′-nucleotidase plays a role in breakdown of messenger RNA and its activity in control liver could be considerably lower periportally because plasma protein synthesis mainly takes place in this area. 5′-Nucleotidase activity may well be decreased after operation for accumulation of messenger RNA for enhanced plasma protein synthesis in order to compensate for 67 per cent of the liver cell functions lost during partial hepatectomy.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cbf.290060109
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