JaLCDOI 10.18926/AMO/32426
FullText URL fulltext.pdf
Author Okimasu, Eiji| Moromizato, Yasunori| Watanabe, Sadahiro| Sasaki, Junzo| Shiraishi, Noriyuki| Morimoto, Yasuko M| Miyahara, Masanobu| Utsumi, Kozo|
Abstract <p>We studied the effect of glycyrrhizin, a compound known as an anti-inflammatory and antiallergic drug, on the membrane permeability change induced by phospholipase A2 (PLA2) and on platelet aggregation. Glycyrrhizin was found to inhibit the PLA2-induced carboxyfluorescein (CF) release from D,L-dipalmitoyl phosphatidylcholine (DPPC) liposomes. Part of this inhibitory effect of glycyrrhizin on PLA2 is accounted for by the physical state of the substrate, the DPPC liposome membrane. Glycyrrhizin also inhibited collagen-induced platelet aggregation in a concentration dependent manner, which may in part account for its inhibitory effect on PLA2.</p>
Keywords phosholipase A2 glycyrrhizin liposome platelet aggregation
Amo Type Article
Published Date 1983-10
Publication Title Acta Medica Okayama
Volume volume37
Issue issue5
Publisher Okayama University Medical School
Start Page 385
End Page 391
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 6689106
Web of Sience KeyUT A1983RN98400001
JaLCDOI 10.18926/AMO/31915
FullText URL fulltext.pdf
Author Watanabe, Sadahiro| Takehara, Yoshiki| Fujii, Yoshitaka| Okimasu, Eiji| Moromizato, Yasunori| Sasaki, Junzo|
Abstract <p>To investigate the involvement of actin filaments in concanavalin A (Con A)-induced cap formation and cytochalasin B (CB)-induced zeiotic knob migration, the distribution of F-actin was studied in Con A-treated and CB-treated Ehrlich ascites tumor cells (EATC) by fluorescence microscopy using heavy meromyosin conjugated with a fluorescent dye, N-(7-dimethylamino-4-methylcoumarinyl) maleimide, (DACM-HMM). In non-treated cells, the diffuse fluorescence of DACM-HMM was observed in the cytoplasm, particularly intensely under the plasma membrane and around the nucleus. In Con A- and CB-treated cells, the fluorescence was seen at Con A-induced-capped and CB-induced-knob-accumulated regions. This fluorescence was more intense in CB-treated cells. To study the actin filaments in these fluorescent regions more clearly, the soluble components of the cells were eliminated by treatment with Triton X-100 or saponin solution containing a low concentration of glutaraldehyde, and the detergent-treated and saponin-treated cells were observed under a transmission electron microscope. Concentrated actin filaments were observed directly beneath the Con A-induced capping area and CB-induced zeiotic knob-accumulation area. The area of concentrated actin filaments appeared to correspond to the electron dense area observed in the identical region in the cells fixed without detergent treatment. More actin filaments were observed in CB-treated cells than in Con A-treated ones.</p>
Keywords DACM-HMM Ehrlich ascites tumor cells concanavalin A cytochalasin B actim capping
Amo Type Article
Published Date 1986-12
Publication Title Acta Medica Okayama
Volume volume40
Issue issue6
Publisher Okayama University Medical School
Start Page 301
End Page 311
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 3825593
Web of Sience KeyUT A1986F275800004
JaLCDOI 10.18926/AMO/31734
FullText URL fulltext.pdf
Author Moromizato, Yasunori| Watanabe, Sadahiro| Sasaki, Junzo|
Abstract <p>Concanavalin A (Con A) induced cap formation in rat ascites hepatoma cells (AH7974). In these Con A-treated cells, the association of cytoplasmic proteins with cell membranes was suggested by observing their Triton shells. The transition from G-actin to F-actin occurred in these cells. The association of membrane lipid with cytoplasmic proteins extracted from AH cells was studied by the isolation of protein-bound liposomes and phase transition release. The analysis of isolated liposomes revealed that many cytoplasmic proteins which specifically associated with liposomes were cytoskeletal elements including F-actins. The association of proteins with liposomes was affected by the lipid composition of the liposomal membrane and by the Ca2+ concentration of the incubation medium. The strong interaction of liposomal membrane with cytoplasmic proteins or isolated cytoskeletal proteins was demonstrated also by phase transition release using carboxy fluorescein-containing liposomes. These experiments showed that there was a strong affinity between lipid membrane and cytoskeletal elements including F-actins and that the amount of F-actin increased due to Con A treatment. The association of the submembranous microfilaments with the cell membrane may contribute to capping of the cells caused by Con A.</p>
Keywords concanavalin A actins liposomes phase trasition release
Amo Type Article
Published Date 1987-08
Publication Title Acta Medica Okayama
Volume volume41
Issue issue4
Publisher Okayama University Medical School
Start Page 145
End Page 154
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 3661239
Web of Sience KeyUT A1987J833200001
JaLCDOI 10.18926/AMO/31288
FullText URL fulltext.pdf
Author Sasaki, Junzo| Imanaka, Masaaki| Watanabe, Sadahiro| Otsuka, Nagayasu| Nakamoto, Shu| Mori, Masaharu|
Abstract <p>The effect of cytochalasin B (CB) on the surface structure of Ehrlich ascites tumor cells was investigated using the scanning electron microscope. The effect occurs in two steps: formation of zeiotic knobs on the cell surface and subsequent grouping of the knobs at one pole of the cell. The early step of zeiotic knob formation occurs at low concentrations of CB (0.5-1 microgram/ml) at 37 degrees C and at high concentrations of the drug (5-10 microgram/ml) at low temperature but within 1 min at 37 degrees C. This step is only partially inhibited by 5 x 10(-3) M sodium azide. The subsequent grouping of zeiotic knobs lasts for more than 2 min at 37 degrees C and occurs only in the case of high concentrations of CB. It is inhibited by sodium azide and is often associated with grouping of the microvilli, which are then lost from all of the cell surface except the area of knob-grouping.</p>
Keywords cytochalasin B Ehrlich ascites tumor cells zeiosis scanning electron microscopy.
Amo Type Article
Published Date 1981-06
Publication Title Acta Medica Okayama
Volume volume35
Issue issue3
Publisher Okayama University Medical School
Start Page 197
End Page 204
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 6457509
Web of Sience KeyUT A1981MD16600005
JaLCDOI 10.18926/AMO/30995
FullText URL fulltext.pdf
Author Sasaki, Junzo| Watanabe, Sadahiro| Nomura, Takako| Fujiwara, Tazuko| Ogura, Hajime|
Abstract <p>The cytoskeletons of two established chick embryo cell (CEC) lines were examined by fluorescence and electron microscopy and compared with those of control cells and cells transformed by Rous sarcoma virus (RSV). In normal CEC, many stress fibers were observed. On the other hand, stress fibers were disorganized in nontransformed spontaneously established CEC, non-tumorigenic CEC partially transformed with a chemical carcinogen, and tumorigenic RSV-transformed CEC. In the normal CEC, actin filaments formed several bundles along the processes of the cell. Stereo-images of the peripheral region revealed bundles of filaments which were located along the attached side to the substrate. A fine well preserved network of filaments was also observed. On the other hand, in spontaneously established, partially transformed and RSV-transformed CEC, a fine network of filaments, but no actin cables, was found. These results support previous evidence that the cytoskeletal changes themselves are not directly related to the transformation or tumorigenicity of cells. </p>
Keywords chick embryo cells cytoskeleton actin Triton X-100 Rous sarcoma virus.
Amo Type Article
Published Date 1988-08
Publication Title Acta Medica Okayama
Volume volume42
Issue issue4
Publisher Okayama University Medical School
Start Page 193
End Page 200
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 3177004
Web of Sience KeyUT A1988P884600002
JaLCDOI 10.18926/AMO/30858
FullText URL fulltext.pdf
Author Ogura, Hajime| Fujiwara, Tazuko| Watanabe, Sadahiro| Sasaki, Junzo|
Abstract <p>The effects of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on the organization of cytoskeleton and growth of normal and established chick embryo cells (CEC) were studied. The cytoskeleton of normal CEC formed stress fibers, while that of the CEC lines established in our laboratory formed no stress fibers. TPA treatment of normal CEC resulted in disorganization of the stress fibers into amorphous structure, while that of the established CEC lines induced no reorganization of the cytoskeleton. TPA had no promotional effect in vitro or in vivo on tumor growth in normal or the established CEC.</p>
Keywords 12-O-tetradecanoyl-phorbol-13-acetate established chick embryo cell lines cytoskeleton stress fiber anchorage-independent growth
Amo Type Article
Published Date 1989-08
Publication Title Acta Medica Okayama
Volume volume43
Issue issue4
Publisher Okayama University Medical School
Start Page 249
End Page 252
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 2801188
Web of Sience KeyUT A1989AP79100008
JaLCDOI 10.18926/AMO/30662
FullText URL fulltext.pdf
Author Sasaki, Junzo| Imanaka, Masaaki| Watanabe, Sadahiro| Mori, Masaharu| Nakamoto, Shu| Kirizuka, Keizi| Otsuka, Nagayasu|
Keywords cytochalasin B Ehrlich ascites tumor cells cappong zeiosis cationized ferritin
Amo Type Brief Note
Published Date 1982-08
Publication Title Acta Medica Okayama
Volume volume36
Issue issue4
Publisher Okayama University Medical School
Start Page 307
End Page 312
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 6890303
Web of Sience KeyUT A1982PE61100008
JaLCDOI 10.18926/AMO/30330
FullText URL fulltext.pdf
Author Watanabe, Sadahiro|
Abstract <p>Cepharanthine, a biscoclaurine alkaloids which interact with biomembranes, has been found to inhibit platelet aggregation. The effects of this drug on morphological and physiochemical phenomena following collagen-induced platelet stimulation were investigated. In the presence of cepharanthine, stimulated platelets became spherical, but did not form pseudopoda , nor did they become aggregated. Physiochemical reactions such as accelerated oxygen consumption, release of membrane-bound Ca2+, release of Ca2+ into the extracellular medium and deporalization of the membrane potential were all inhibited by cepharanthine. Using D,L-dipalmitoyl phosphatidylcholine liposomes as the substrate, cepharanthine was shown to inhibit phospholipase A2 activity. These results suggest that the changes in the membrane following the interaction of collagen with its receptor are important for platelet activation. Cepharanthine may inhibits these membrane state changes, thus blocking all subsequent reactions.</p>
Keywords platelet aggregation cepharanthine electron microscopy phospholipase A<sub>2</sub> liposome
Amo Type Article
Published Date 1984-04
Publication Title Acta Medica Okayama
Volume volume38
Issue issue2
Publisher Okayama University Medical School
Start Page 101
End Page 115
ISSN 0386-300X
NCID AA00508441
Content Type Journal Article
language 英語
File Version publisher
Refereed True
PubMed ID 6731025
Web of Sience KeyUT A1984SN81800002