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Volume 6 (1981)
- Issue 4 Pages 301-
- Issue 3 Pages 201-
- Issue 2 Pages 93-
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Volume 6, Issue 1
Displaying 1-11 of 11 articles from this issue
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Toru Imamura, Masatoshi Beppu, Tadao Terao, Toshiaki Osawa1981 Volume 6 Issue 1 Pages 1-10
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSRequirements for the cross-linking of lectin receptors in the internalization of lectins into Balb/c 3T3 cells were investigated with lectins of various valences. 125I-labeled tetravalent concanavalin A (Con A) was inter-nalized rapidly within 60 min, whereas divalent Con A was internalized only slightly after 60 min, and no monovalent Con A was, even after 120 min. How-ever, additional treatment of the cells which bound either monovalent or divalent Con A with anti-Con A antibody resulted in the rapid internalization of lectin. Internalization of other 125I-labeled lectins (wheat germ agglutinin, Lens culinaris agglutinin and Pisum sativum agglutinin) also appeared to be dependent on their valences. These results suggest that the cross-linking of lectin receptors is required for lectin take up in Balb/c 3T3 cells. When these cells were treated with dansyl cadaverine (500μM) and monoethylamine (90 mM), both potent inhibitors of transglutaminase, the take up of [125I]Con A was inhibited by 80% and 50%, respectively. By contrast, cytochalasin B and colchicine, inhibitors of cytoplasmic structures, inhibited [125I]Con A internalization by 47% and 25%, at the highest concentrations which produce no morphological changes in the cells (10-4 M). These data suggest that cellular transglutaminases are essential in Con A internalization into Balb/c 3T3 cells, and that microfilaments and microtubules have only a partial role.View full abstractDownload PDF (1110K) -
Kazuko Miyakawa-Iida1981 Volume 6 Issue 1 Pages 11-22
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSVarious lectins were examined for their ability to induce phagocytosis of sheep erythrocytes by peritoneal macrophages of the guinea pig and mouse. Phaseorous vulgaris lectin-L (PHA(L)) induced the phago-cytosis of erythrocytes by guinea pig macrophages and wheat germ agglutinin (WGA) that of erythrocytes by mouse macrophages. Concanavalin A (Con A) induced little ingestion by either macrophage, although it induced much attachment of the erythrocytes to both. The PHA(L)-induced phagocytosis of erythrocytes by guinea pig macrophages was inhibited specifically by N-acetyl-D-galactosamine. PHA(L) linked the guinea pig macrophages and sheep erythrocytes. Con A did not suppress the PHA(L)-induced phagocytosis of erythrocytes by guinea pig macrophages. These results suggest that the attach-ment of erythrocytes to macrophages is not sufficient for phagocytosis and that certain sites on the surface of the macrophages must be stimulated for phago-cytosis to occur. Soluble antigen-antibody complexes, which block the Fc receptors of macrophage and other cell types, inhibited both the antibody-induced and the PHA(L)-induced ingestion of erythrocytes by guinea pig macrophages. A prior incubation of guinea pig macrophages with high con-centrations of PHA(L) suppressed the ingestion of erythrocytes which was induced by PHA(L), but not that induced by antibody. This is evidence that some relation exists between the Fc receptors and the PHA(L) binding site that is responsible for the induction of phagocytosis.View full abstractDownload PDF (1249K) -
Kozi Matuoka, Youji Mitsui1981 Volume 6 Issue 1 Pages 23-33
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSGrowth of human diploid fibroblasts on the cell sheets treated with various fixatives and enzymes was examined in order to investigate the mechanism of the density-dependent inhibition of cell proliferation. Growth was inhibited about 40 % when fibroblasts were cultured on glutaraldehyde-fixed cell sheets of late passage cells, compared with cell growth on perchloric acid-fixed cell sheets or in control cultures without cell sheets. Treatment of glutaraldehyde-fixed cell sheets with heparitinase or nitrous acid caused the complete loss of the inhibitory effect. When fibroblasts were cultured on glutaraldehyde-fixed cell sheets derived from early, middle and late passage cell cultures, cell growth on the late passage cell sheets showed greater in-hibition. These inhibitory effects of the cell sheets correlated well with both the relative amount of heparan sulfate to the total glycosaminoglycans in the cell layer and to the saturation density at each passage. These findings indicate that heparan sulfate (or its complex) on the cell surface is involved in the density-dependent inhibition of cell proliferation.View full abstractDownload PDF (1103K) -
Masao Hyodo, Kenshi Suzuki1981 Volume 6 Issue 1 Pages 35-42
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThree peaks of DNA-dependent ATPase activity were found in an extract of cultured mouse FM3A cells by fractionation with phosphocel-lulose column chromatography. These ATPase activities were decreased or missing when the enzymes were extracted from non-growing cells arrested at saturation density, evidence that these activities are related to the regulation of cell growth. Our characterization of these enzyme activities showed differ-ences in their dependencies on single-stranded DNA, optimal pH, the Mg++ requirement and sensitivity to 2-mercaptoethanol.View full abstractDownload PDF (782K) -
Akihiko Ogura1981 Volume 6 Issue 1 Pages 43-50
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSStrong shaking in a solution containing 5% ethanol quickly removed a11 the cilia except those in the buccal cavity from a paramecium. The cilia were cut just distal to the axosome. Ciliary regrowth took place soon after transfer to a medium containing no ethanol. Scanning electron microscopy showed that there were regional differences in the rate of ciliary repopulation. Colchicine reversibly blocked reciliation.View full abstractDownload PDF (874K) -
Hiroshi Sakagami, Senwa Unten, Minoru Takeda, Ken Takeda, Kunio Konno1981 Volume 6 Issue 1 Pages 51-59
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe Ficoll-Urografin density gradient method was used to separate differentiated mouse myeloid cells (M1), and the properties of the fractionated cellpopulations were investigated.
During differentiation in vitro, M1 cells produced large adherent cells. These adherent cells showed an increased cell size and a decreased ratio of nucleus size to cell size (N/C ratio) in comparison with untreated M1 cells and nonadherent cells. With discontinuous Ficoll-Urografin density gradient centrifugation, adherent cells could be separated into subfractions with low N/C ratios (d = 1.033-1.054, rich in macrophage-like cells); those with inter-mediate N/C ratios (d= 1.054-1.059, rich in cells in the intermediate stages of differentiation); and those with high N/C ratios (d =1.059-1.067, rich in myeloblastic cells). Almost all the untreated M1 cells and nonadherent cells were banded in the high density region (d = 1.059-1.067).
Both phagocytic and lysozymic activities were highest in the lowest density band. Elevated lysosomal enzyme activity in the highest density fraction of the fractionated cells indicates that these cells may differ from M1 cells in their biological activity.View full abstractDownload PDF (858K) -
Kenji Sorimachi, Akira Niwa, Yosihiro Yasumura1981 Volume 6 Issue 1 Pages 61-68
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSRat hepatoma cells (R-Y121B) which can grow under serum-free conditions were used to study the true effect of serum on the induction of the liver-specific enzymes, tyrosine aminotransferase and phenylalanine hydroxylase. R-Y121B was derived from Reuber hepatoma cells (H4-II-E).
Serum and dexamethasone similarly induced tyrosine aminotransferase and phenylalanine hydroxylase. Tyrosine aminotransferase activity increased gradually until the 8th hour when it reached a plateau. The increase in phenyl-alanine hydroxylase activity was much slower until the 12th hour, then a strik-ing increase in phenylalanine hydroxylase activity occurred up to the 24th hour. Insulin also increased tyrosine aminotransferase activity up to the 4th to 6th hour, then this activity gradually decreased.
Insulin did not, however, induce phenylalanine hydroxylase activity. The increase in both enzyme activities due to serum or dexamethasone after 24 h of incubation was partially abolished in the presence of insulin.
The degree of the induction of both enzymes by serum differed greatly for t he various preparations of sera, but no clear correlation between the prep-aration of sera and enzyme activities was found. Thus, we concluded that serum, which contains hormones, including insulin and glucocorticoids, as well as other unknown factors, plays an important role in the regulation of liver-specific enzyme activities.View full abstractDownload PDF (832K) -
Hiroshi Miyamoto, Toshitaka Ikehara, Tetsuhiro Sakai, Kenichi Kaniike1981 Volume 6 Issue 1 Pages 69-78
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSTo obtain evidence of the action of the intracellular redox system as a regulating factor of membrane K+ transport in HeLa cells, we used an artificial electron mediator, phenazine methosulfate (PMS). An addition of PMS to the incubation medium increased the intracellular accumulation of Rb+ as an analog of K+. This increase, which was ouabainsensitive, was shown to be due to the stimulation of active Rb+ transport. The rate of ouabainsensitive Rb+ uptake was a linear function of the cellular bulk ATP level. When cells were treated with 20 μM PMS, the linear curve showed a parallel shift upward. The range of the shift, the PMS-stimulated part of the Rb+ uptake, was independent of the ATP level. The intracellular level of Rb+ plus K+, which was equal to the K+ level in cells incubated in normal medium, was elevated slightly, but Na+ level remained unchanged. These results indicated that the stimulation of Rb+ uptake had no effect on changes in the intracellular levels of monovalent cations. The maximal rate of ouabainsensitive Rb+ uptake, Jmax, was increased, but the apparent Km in relation to extracellular Rb+ was unaffected. The specific binding of [3H]ouabain was not enhanced. Thus, the total number of Rb+ binding sites and the affinity of Rb+ to those sites would not be affected significantly. We concluded that the stimulating action of PMS is due either to the acceleration of Rb+ pumping at each Na+, K+-pump or to activation of the resting pumps.View full abstractDownload PDF (909K) -
Takao Matsuura, Hisao Ueyama, Hiroshi Nakayasu, Kiyoshi Ueda1981 Volume 6 Issue 1 Pages 79-82
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSTwo procedures to isolate the nuclear matrix from rat liver nuclei were developed. These prevent contamination by nuclear membrane fragments and consist of (A) three consecutive treatments with 1 % Triton X-100 buffer, DNase I digestion and high salt extraction; and (B) a modification of Berezney's method in that isolated nuclei were washed three times with 1 % Triton X-100 buffer in the first step. The nuclear matrices obtained from rat liver nuclei by these procedures consist largely of protein (88.3-88.6 %) with small amounts of RNA (6.5-10.6%), DNA (0.9-4.6%) and phospholipid (0.2-1.2%). Sodium dodecyl sulfate-acrylamide gel electrophoresis of the nuclear matrix proteins gives three major polypeptides with molecular weights of 60, 000-80, 000.View full abstractDownload PDF (344K) -
Tadao Ohno, Ichiro Kaneko1981 Volume 6 Issue 1 Pages 83-86
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSThe platelet-derived growth factor (PDGF), a potent mitogen for normal human fibroblasts, shows reduced activity in medium containing regular levels of Ca++. A double reciprocal plot of the growth rate of IMR-90 cells versus the Ca++ concentration in the presence or absence of PDGF showed a common intercept on the ordinate, which gives a minimum doubling time of 20 h for middle aged cells. This is evidence of a competitive growth stimulation by PDGF and Ca++ that differs from the non-competitive mode of action of EGF by which is also reduced the requirement of extracellular Ca++ for normal human cell growth.View full abstractDownload PDF (426K) -
Hoyoku Nishino, Chin-Bin Pak, Jiro Imanishi, Kazuo Nakanishi, Masaru F ...1981 Volume 6 Issue 1 Pages 87-92
Published: 1981
Released on J-STAGE: April 18, 2008
JOURNAL FREE ACCESSCell surface fibronectin, an adhesive glycoprotein which is important in maintaining the normal phenotype of cells, was checked with cytofluorometry using an indirect immunofluorescent technique. This method enabled us to measure the amount of fibronectin not only in single whole cells, but in uniformly distributed cells as a whole. The fibronectin content in a sparse culture of human fibroblasts increased linearly until the 4th day after inoculation. In more prolonged cell cultures, fibronection increased at a higher rate than that in the earier culture period. In a confluent culture re-fed with fresh medium containing 10% fetal calf serum, the amount of fibronectin increased and appeared as a matrix substance in the extracellular space. In contrast, in a confluent cell culture re-fed with serum-free medium, the amount of fibronectin decreased for several days.View full abstractDownload PDF (470K)
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