Biomedical subjects

K Tasaka

Publications and source records attributed to K Tasaka.

At least 127 records · Page 7Linked to original sources

PubMed1992

Analysis of tumor necrosis factor and lymphotoxin secreted by incubation of lymphokine-activated killer cells with tumor cells.

This study investigated the secretion of a tumor necrosis factor (TNF) and lymphotoxin (LT) from lymphokine-activated killer (LAK) cells during co-culture with glioblastoma cell lines, autologous glioma cells, and other non-gliomatous tumor cell lines (K562 and Daudi). Cytokine secretion from peripheral blood mononuclear cells (PBMC) was also examined. The TNF activity of culture supernatants was measured by L cell cytotoxic assay, and a neutralization test using anti-TNF and/or anti-LT antibodies determined whether the cytotoxic activity was due to TNF or LT. The results show that LAK cells secrete both TNF and LT during monoculture and release increased amounts of TNF and LT with non-gliomatous tumor cell stimulation, but PBMC secrete only TNF with tumor cell stimulation. Glioblastoma or anaplastic astrocytoma cells, however, did not stimulate cytokine secretion from either LAK cells or PBMC. This indicates a discrepancy between the capability of LAK cells to lyse malignant glioma cells and cytokine secretion from LAK cells, and suggests that malignant glioma cells may produce some factors which inhibit cytokine secretion from LAK cells.

Astrocytoma↗

PubMed1992

Antiallergic effect of epinastine (WAL 801 CL) on immediate hypersensitivity reactions: (I). Elucidation of the mechanism for histamine release inhibition.

Epinastine caused an inhibition of histamine release from rat peritoneal mast cells induced by both antigen-antibody reaction and compound 48/80. Epinastine was similarly effective in inhibiting compound 48/80-induced histamine release not only from isolated rat peritoneal mast cells but also from rat mesenterial pieces. Also, histamine release from lung pieces obtained from actively sensitized guinea pigs after exposure to antigen challenge was markedly inhibited by epinastine. The drug was effective in inhibiting not only Ca2+ uptake into lung mast cells in actively sensitized guinea pigs but also Ca2+ release from the intracellular Ca store of rat peritoneal mast cells exposed to both compound 48/80 and substance P. No significant changes were observed in phosphodiesterase activity in rat peritoneal mast cells treated with epinastine, while adenylate cyclase activity was augmented by epinastine. Epinastine has no inhibitory effect on histamine release induced by Ca2+ or IP3 from permeabilized mast cells. However, the drug significantly and dose-dependently suppressed calmodulin activity suggesting that histamine release inhibition due to epinastine may be partly attributable to Ca(2+)-calmodulin dependent process(es). The drug caused no visible changes in thermodynamic behavior of lipids, either in order parameter or in differential scanning calorimetry, indicating that the drug has no influence on membrane fluidity.

Adenylyl Cyclases↗

PubMed1992

Antiallergic effect of epinastine (WAL 801 CL) on immediate hypersensitivity reactions: (II). Antagonistic effect of epinastine on chemical mediators, mainly antihistaminic and anti-PAF effects.

Anti-histamine and anti-PAF effects of epinastine were tested in rats, guinea pigs and rabbits. Epinastine showed a potent histamine H1-blocking effect, but the potency was slightly less than that of ketotifen in histamine-induced contraction of guinea pig ileum and histamine-induced cutaneous reactions in rats. In histamine-induced dye leakage into the nasal cavity tested in rats, the drug was slightly more potent than ketotifen and azelastine. Epinastine as well as ketotifen suppressed rabbit platelet aggregation induced by PAF at higher concentrations compared with WEB 2086, a specific PAF-antagonist. In the bronchospasm induced by PAF in guinea pigs, epinastine was more effective than ketotifen in inhibiting the bronchoconstriction, while it showed no remarkable effect on the hypotension induced by PAF. Epinastine caused a potent antagonistic effect on LTC4-induced contraction of isolated guinea pig trachea. In conclusion, the potent anti-histamine, anti-PAF and anti-LT effects of epinastine may significantly contribute to its antiallergic activity.

Animals↗

PubMed1992

Antiproliferative cytokines secreted by lymphokine-activated killer cells stimulated with tumor cells.

Antiproliferative cytokine secretion by lymphokine-activated killer (LAK) cells during coculture with glioblastoma cell lines, autologous glioma cells, and nongliomatous tumor cell lines (Daudi and K562 cells) was assessed, as was the antiproliferative activity of the culture supernatants against the T98G (glioblastoma) cell line. A neutralization test using agents against interferon-gamma (IFN-gamma), tumor necrosis factor (TNF), and lymphotoxin (LT) showed that antiproliferative activity was due to IFN-gamma, but not to TNF or LT. Nongliomatous tumor cells stimulated LAK cells to secrete cytokines, but gliomatous tumor cells did not. It was found that there is a discrepancy between the LAK cell capability to lyse malignant glioma cells and the ability to secrete cytokines. This may be due to the factors secreted by glioblastoma cells.

Astrocytoma↗

PubMed1992

Histamine leukocytosis. I. Effect of histamine on peripheral leukocyte counts.

The effect of chronic administration of histamine on the number of cells in peripheral blood of dogs, rabbits and guinea pigs was tested by single and consecutive intramuscular injections of histamine in a beeswax-sesame oil mixture. Leukocytosis due to increased numbers of neutrophils occurred in all animals after single injections of histamine in beeswax, although erythrocytes and hematocrit values were unaffected in all species. When injection of histamine was repeated on consecutive days, the extent of leukocytosis subsided in some cases; however, the simultaneous administration of aminoguanidine restored leukocytosis. Single or daily injections of the beeswax-sesame oil mixture without histamine had none of these effects in any animals tested. Although simultaneous injections of histamine and H1 receptor antagonists did not alter histamine effects, the combined administrations of histamine and H2 receptor blocking agents suppressed histamine-induced leukocytosis.

Animals↗

PubMed1992

Histamine leukocytosis. II. Source of histamine leukocytosis.

Leukocytes were labelled by intravenous injection of tritiated thymidine (3H-thymidine) in dogs to discover the source of the increased number of neutrophils in the circulating blood after injection of histamine in beeswax. Dogs with normal hemograms were given 1.0 mCi/kg of 3H-thymidine alone, and in different sequences, with histamine in beeswax. When 3H-thymidine was given during maintained histamine leukocytosis, labelled granulocytes appeared in and disappeared from the blood earlier than in control tests and the number of labelled cells was greater in the histamine-treated animals. Administration of histamine in beeswax 3 days after injection of 3H-thymidine also induced the premature appearance and disappearance of labelled neutrophils in the circulating blood. It was concluded that leukocytosis induced by the chronic action of histamine is due to 1) stimulated proliferation and differentiation of neutrophil precursor cells in the bone marrow and 2) the release of mature leukocytes from the bone marrow.

Animals↗

PubMed1991

Involvement of the microtubular system in the endothelin-1 secretion from porcine aortic endothelial cells.

The effects of certain microtubule-disrupting agents on endothelin-1 (ET-1) secretion from porcine aortic endothelial cells were studied. When endothelial cells were treated with thrombin (1 unit/mL), a significant increase in ET-1 secretion was detected in the incubation medium, while ET-1 secretion in the medium was diminished when the cells were treated simultaneously with either colchicine or vinblastine (10(-8)-10(-6) M). In such cases, however, the ET-1 content detected in the cells increased dose-dependently in accordance with the concentrations of the microtubule-disrupting agents. The intracellular accumulation of ET-1 was observed both in mitochondrial and microsomal fractions. On the other hand, thrombin produced a significant increase in polymerized tubulin content without affecting the total tubulin content. A thrombin-induced increase in the intracellular Ca2+ concentration of endothelial cells was inhibited by treatment with either colchicine or vinblastine. These results seem to indicate that the microtubular system may play an important role in ET-1 secretion from endothelial cells.

Animals↗

PubMed1991

Superoxide anion increases intracellular pH, intracellular free calcium, and arachidonate release in human amnion cells.

We determined the effects of superoxide anion, produced by addition of xanthine oxidase to hypoxanthine, on the intracellular pH (pHi) and intracellular free calcium concentration ([Ca2+]i) and release of arachidonate in human cultured amnion cells. Superoxide anion induced a prompt increase of pHi and subsequent increase of [Ca2+]i. The evoked pHi was inhibited by pretreatment with anion channel blockers but not affected by omission of extracellular Na+ or addition of amiloride. The increase of [Ca2+]i was inhibited significantly by the absence of extracellular calcium or by the addition of a calcium channel blocker, cobalt. NH4Cl, which can generally increase pHi, also increased [Ca2+]i of amnion cells. But the increase of [Ca2+]i induced by the NH4Cl was significantly less than that induced by the amount of superoxide anion causing a similar increase in pHi. These results show that superoxide anion, crossed through anion channel in membrane, increased [Ca2+]i at least partially via increase of pHi and that the calcium mobilization was dependent on both extracellular and intracellular sources. Superoxide anion induced the release of arachidonate in a dose-dependent manner and this induction was inhibited by omission of extracellular calcium. These data suggest that the release of arachidonate was dependent on the increase of [Ca2+]i. We also determined the viability of cells in the presence of superoxide anion by flow cytometry. Superoxide anion at the levels used in these experiments did not change the percentage of viable cells. These findings suggested that superoxide anion may regulate biological functions in amnion cells via pHi, [Ca2+]i mobilization, and the release of arachidonate without damaging the cells.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

PubMed1991

Structure-activity relationships of sarafotoxins: chemical syntheses of chimera peptides of sarafotoxins S6b and S6c.

The three chimera peptides of sarafotoxins S6b (SRTb) and S6c (SRTc), [Thr2]SRTb, [Asn4]SRTb and [Glu9]SRTb, were synthesized chemically. From the comparisons of lethality, vasoconstrictor activity and receptor binding activity of SRTb, SRTa [( Asn13]SRTb), SRTc [( Thr2,Asn4,Glu9,Asn13]SRTb), [Thr2]SRTb, [Asn4]SRTb and [Glu9]SRTb, it appears that the Lys9 to Glu9 substitution greatly diminishes these activities while the Lys4 to Asn4 substitution does not affect them, and the Ser2 to Thr2 substitution or the Tyr13 to Asn13 substitution slightly diminishes these activities. These results suggest that the very low activities of SRTc are caused mainly by the Lys9 to Glu9 substitution, but not by the Ser2 to Thr2 substitution, which was suggested to be responsible for the weak bioactivities of SRTd [( Thr2,Ile19]SRTb).

Amino Acid Sequence↗

PubMed1991

Comparison of the amino acid and nucleotide sequences between human and two guinea pig major basic proteins.

By means of reverse-phase HPLC, 2 different proteins were obtained from apparently purified pig eosinophil major basic protein (MBP) and these proteins were named GMPB1 and GMBP2. It was revealed that these 2 components of MBP have similar molecular weights and pI values, although the amino acid compositions were slightly different. In the previous study, we cloned and sequenced GMPB1 cDNA. Here we obtained another clone by plaque hybridization using a screening probe synthesized by means of polymerase chain reaction. After sequencing, it became apparent that this clone corresponded to GMBP2. As in the case of GMBP1, the cDNA of GMBP2 encoded pre-proGMBP2 with 3 domains; signal peptide, acidic pro-portion, and mature GMBP2. By comparing the sequences of GMBP1 and GMBP2, it was revealed that the proteins were quite similar to each other. In addition, their sequences also resembled those of human MBP, especially in the basic domain of mature protein; but no such similarity existed in the pro-portion. Although the molecular weights determined by SDS-PAGE of guinea pig and human MBPs were 11,000 and 9,300, respectively, the calculated molecular weights of these 3 MBPs were all 13.8 kDa. The calculated pI values of GMBP1, GMBP2 and human MBP were 11.7, 11.3 and 11.6, respectively. By means of Harr plot analysis, it was revealed that the amino acid sequences, not only in signal peptides but also in the basic domains of mature proteins, were well conserved between guinea pig and human MBPs.

Amino Acid Sequence↗

PubMed1991

Presence of non-selective type of endothelin receptor on vascular endothelium and its linkage to vasodilation.

We studied the role of non-selective type (ETB) of endothelin (ET) receptor in the vasculature, using a ligand specific to the ETB receptor, [Glu9]-sarafotoxin S6b ([Glu9]SRTb). Endothelium-containing rat thoracic aorta possessed specific binding sites for 125I-[Glu9]SRTb, which were almost eliminated by removal of the endothelium, while ET-3-specific binding sites were not detected in the endothelium-intact rat aorta. Only ETB receptor was detected in the membranes from the endothelium of porcine thoracic aorta. [Glu9]SRTb exerted only vasodilation in rat aortic ring. These findings indicate that ETB receptors are located on vascular endothelium and linked to vasodilation.

Animals↗

PubMed1991

Purification of gonadotropes and intracellular free calcium oscillation. Effects of gonadotropin-releasing hormone and interleukin 6.

The intracellular free calcium concentration ([Ca2+]i) in single gonadotropes was measured with a calcium-sensitive fluorescent dye indo-1 or fura-2 and a digital imaging fluorescence microscopic system to determine how interleukin-6 (IL-6) increases release of gonadotropins. IL-6 induced an increase in the basal [Ca2+]i or the amplitude of spontaneous oscillation of [Ca2+]i in gonadotropes in a mixed population. Gonadotropin-releasing hormone (Gn-RH) induced a biphasic increase in [Ca2+]i, a transient increase, and then a prolonged increase. These effects were inhibited by the absence of extracellular calcium or pretreatment with calcium channel blockers, cobalt or nifedipine. Next, purified gonadotropes were prepared by fluorescence-activated cell sorting and argon laser treatment of the cells. Gonadotropes labeled with anti-luteinizing hormone antibody were sorted by fluorescence-activated cell sorting and then cultured as monolayers for 24-48 h. In this way, gonadotropes were concentrated from 5-10% to 70-85% from whole pituitary cells. After relabeling with anti-luteinizing hormone antibody, 100% purified gonadotropes were obtained by killing other types of cells with an argon laser. Gonadotropin-releasing hormone induced almost the same responses of [Ca2+]i in the purified cell population as in the mixed cell population, but IL-6 did not affect [Ca2+]i in the purified gonadotropes. These results suggest that IL-6 affects calcium mobilization in gonadotropes indirectly via paracrine pathways.

Animals↗

PubMed1991

Sequencing and cloning of the cDNA of guinea pig eosinophil major basic protein.

Major basic protein (MBP) purified from guinea pig eosinophils elicited histamine release from rat peritoneal mast cells at concentrations higher than 3 micrograms/ml both in the presence and in the absence of extracellular Ca2+. After reverse-phase high-performance liquid chromatography, it was revealed that MBP was composed of two different proteins with quite similar molecular weights and pI values, although the amino acid compositions were slightly different. The partial amino acid sequence of one of these MBPs was determined and the primers for the polymerase chain reaction (PCR) were synthesized according to the partial amino acid sequence. Using these primers and the cDNAs obtained from guinea pig eosinophils, the PCR was carried out in order to synthesize the hybridization probe of MBP for screening the cDNA library. After screening with 8 x 10(5) clones, a positive clone, which encoded a full length of pre-proMBP, was obtained. According to the sequencing data of this clone, it was revealed that pre-proMBP was composed of 3 domains; signal peptide, acidic domain and mature MBP. The predicted pI value of mature MBP was 11.7, though that of proMBP was 7.8. The homology in the amino acid sequence between guinea pig proMBP and human proMBP was 49.4%, while guinea pig mature MBP was more homologous (58%) to human mature MBP.

Amino Acid Sequence↗

PubMed1991

Role of the cytoskeleton in Ca2+ release from the intracellular Ca store of rat peritoneal mast cells.

In order to study the role of the cytoskeleton in histamine release from mast cells, the effects of cytochalasin D, cholchicine and vinblastine on Ca2+ release from the intracellular Ca store induced by compound 48/80 were investigated by means of a video-intensified microscopy system. When the quin 2-loaded mast cells were stimulated by 0.35 micrograms/ml of compound 48/80, a rapid increase in intracellular Ca2+ was observed. At concentrations higher than 10(-6) M, both colchicine and vinblastine pretreatments significantly inhibited the increase in intracellular Ca2+ concentrations caused by compound 48/80, although cytochalasin D had no effect. When permeabilized mast cells were exposed to potassium-antimonate solution, microtubules became attached to the endoplasmic reticulum, where many dots of Ca-antimonate were observed; in some areas, the microtubules interconnected the endoplasmic reticulum and granules in the mast cells. From the results of the present study, it was assumed that microtubules play some important role in the processes leading to Ca2+ release from the intracellular Ca store.

Aminoquinolines↗

PubMed1991

The existence of filaments connecting the granules and the cell membrane in rat peritoneal mast cells.

SEM images of rat peritoneal mast cells showed that microtubule-like filaments seemed to penetrate the granules and project several branches just beneath the granular surface. Each granule appeared to be a cluster of microgranules. TEM observations frequently revealed microtubules connecting the granule surface to the subplasmalemmal network or to the adjacent granule surface and on some occasions, microtubules also appeared to penetrate the granule membranes. Moreover, TEM revealed that individual granules seemed to consist of a mass of microgranules, each 10-15 nm in diameter; freeze-fracture images showed similar configurations. These findings suggest that the microtubule-like filamentous structures in mast cells play a role corresponding to that of the open canalicular system in platelets.

Animals↗

PubMed1991

Monoclonal IgGs from an autoimmune MRL/Mp-lpr/lpr mouse induce an interleukin-3-dependent myeloid cell line to produce tumor necrosis factor alpha and interleukin-6.

We previously reported that two IgG mAbs, 1D11 and 1G10, derived from an autoimmune MRL/Mp-lpr/lpr(MRL/l) mouse, induced IL-3 synthesis in the IL-3-dependent myeloid cell line, FDC-P2/185-4. In this study, we found that these mAbs induced TNF-alpha and IL-6 production in FDC-P2/185-4 cells. Both TNF-alpha and IL-6 were secreted rapidly within 1 hr after the addition of mAb to the cells. Increases of TNF-alpha and IL-6 mRNA were also observed in FDC-P2/185-4 cells stimulated with MRL/l-derived mAb. The anti-Fc gamma RII mAb 2.4G2 suppressed TNF-alpha and IL-6 production induced by these mAbs. Our results suggest that some IgGs of MRL/l mice may have the capacity to induce cytokine synthesis in Fc gamma R-bearing cells.

Animals↗

PubMed1991

Serum IgG from CBA/K1Jms-lprcg/lprcg mice induces interleukin 3 in an interleukin-3-dependent cell line--possible correlation with lymphadenopathy.

Serum IgG of CBA-K1Jms-lprcg/lprcg (lprcg/lprcg) mice with spontaneous systemic lymphadenopathy supported the proliferation of an IL-3-dependent cell line, FDC-P2/185-4. The lprcg/lprcg IgG induced IL-3 synthesis in FDC-P2/185-4 cells, and cells grew by an autocrine mechanism. There was virtually no time lag between the appearance of lymphadenopathy and an increase of IL-3-inducing activity in the sera. We have previously shown that serum IgG from other autoimmune mice with lymphadenopathy, MRL/Mp-lpr/lpr(MRL/lpr) and C3H/HeJ-gld/gld(C3H/gld), also induces IL-3 synthesis and cell growth in FDC-P2/185-4 cells. Furthermore, neither F1 (lprcg/+) mice between lprcg/lprcg and CBA(-)+/+ nor those (lpr-gld) between C3H-lpr/lpr and C3H/gld showed such IL-3-inducing activity, while those (lprcg-gld) between lprcg/lprcg and C3H/gld showed activity much lower than that of their parental strains but significantly higher than that of normal CBA(-)+/+ mice. This result is consistent with the incidence and degree of lymphadenopathy in these F1 mice. Our results suggest that expression of IgG(s) with cytokine-inducing activity might be controlled by these mutant genes, lpr, gld, and lprcg, and might be related to lymphadenopathy in these mice.

Animals↗

PubMed1991

Augmented interleukin 6 production by rat thyrocytes (FRTL5): effect of interleukin 1 beta and thyroid-stimulating hormone.

This study shows that rat thyroid follicular (FRTL5) cells can produce interleukin 6 (IL-6) spontaneously and that IL-1 beta enhanced the production of IL-6 dose-dependently. In addition, 10 ng/mL of IL-1 beta in combination with 10 to 1,000 microU/mL of thyroid-stimulating hormone (TSH) synergistically enhanced IL-6 production. It is suggested that IL-6 released from thyroid follicular cells may be a costimulator of autoreactive B and T cells in autoimmune thyroid disease and may constitute another link between the immune and endocrine systems.

Animals↗