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51.
Nobuyuki Sasakawa Konosuke Kumakura Satoshi Yamamoto Ryuichi Kato 《Life sciences》1983,33(20):2017-2024
Effects of N-(6-aminohexyl)-5-chloro-1-naph-thalenesulfonamide (W-7), a calmodulin antagonist, on catecholamine (CA) release and 45Ca2+ uptake were studied using cultured bovine adrenal chromaffin cells. W-7 inhibited the carbamylcholine (CCh)-evoked CA release and 45Ca2+ uptake in a concentration-dependent manner. The inhibitory effect of W-7 on CCh-evoked CA release was not overcome either by an increase in extracellular calcium or CCh concentration. Although W-7 inhibited the high K+-evoked CA release and 45Ca2+ uptake, potency of the drug was approximately 50–100 fold less than when inhibiting the CCh-evoked CA release and 45Ca2+ uptake. The inhibitory effects of W-7 were observed both in norepinephrine release and epinephrine release. Moreover, W-7 inhibited the CCh-evoked 45Ca2+ efflux. These results suggest that the inhibition of CA release by W-7 in adrenal chromaffin cells is mainly due to its inhibition of calcium uptake. W-7 may influence the linkage between acetylcholine-receptor and calcium uptake with higher potency than depolarization-dependent calcium entry. 相似文献
52.
Absorption spectra of chlorophyll a in phosphatidylcholine liposomesat different temperatures were analyzed by a curve fitting method.The absorption spectrum was found to be composed of one majorband with a peak at 670671 nm and minor bands with peaksat 650652, 662663 and 684686 nm. Upon coolingbelow the phase transition temperature of the lipid, the componentabsorbing at 670671 nm increased significantly at theexpense of the component absorbing at 662663 nm. No changein the extents of other bands was observed.
1 CIW-DPB Publication No. 795.
2On leave from the Department of Biology, Faculty of Science,Kanazawa University, Marunouchi, Kanazawa 920, Japan. (Received December 20, 1982; Accepted April 27, 1983) 相似文献
53.
Summary Spectinomycin resistant (spc
r) mutants were obtained by treating the cells of E. coli K12, W3637 with nitrosoguanidine. The compositions of ribosomal proteins were analyzed for six out of eleven such spc
r-mutants with chromatography on a carboxymethyl cellulose (CMC) column. The 30s ribosomal subunit from all of the spc
r-mutants was found to contain the altered 30-4 protein component, while no difference was detected in 50s ribosomal proteins between spc
r and spc
s bacteria.Abbreviations used CMC
carboxymethyl cellulose
-
str
streptomycin
-
spc
spectinomycin 相似文献
54.
Masami Matsumoto Yukihiro Shoyama Itsuo Nishioka Hisashi Iwai Satoshi Wakimoto 《Plant cell reports》1989,7(8):636-638
Virus free plants of Rehmannia glutinosa Libosch. var. purpurea Makino were obtained through meristem tip tissue cultures from plants infected with a mixture of tabocco mosaic virus(TMV), a member of the carlavirus group, and an unknown spherical virus. The re-infection rate of the virus free plants by TMV in the field was determined by enzyme linked immunosorbent assay(ELISA). Twenty seven percent of the plants were re-infected during the first year, 31 % by the end of second year, and 63 % by the end of the third year. The yield of root and iridoid glycoside contents gradually decreased each year. These results led to the conclusion that virus infection causes marked decrease of the yield of roots and productivity of secondary metabolites. 相似文献
55.
IL-6 stimulates osteoclast-like multinucleated cell formation in long term human marrow cultures by inducing IL-1 release 总被引:24,自引:0,他引:24
N Kurihara D Bertolini T Suda Y Akiyama G D Roodman 《Journal of immunology (Baltimore, Md. : 1950)》1990,144(11):4226-4230
IL-6 enhances the differentiation of pluripotent hematopoietic stem cells but predominantly affects the differentiation of hematopoietic cells in the granulocyte-macrophage lineage. We have previously shown that multinucleated cells (MNC) with many features of the osteoclast phenotype form in long term human marrow cultures. Addition of rhIL-6 (10 to 100 pg/ml) to these cultures significantly increased MNC formation, with greater than 80% of the MNC expressing an Ag that cross-reacts with the mAb 23c6. This antibody preferentially binds to osteoclasts. rhIL-6 did not enhance MNC formation in marrow cultures treated with 1,25 dihydroxyvitamin D3, a potent stimulator of MNC formation, but significantly increased the percentage of MNC that cross-reacted with the 23c6 mAb. Addition of antihuman IL-1 to cultures treated with rhIL-6 totally inhibited the increase in MNC formation stimulated by rhIL-6. In contrast, anti-IL-1 did not affect MNC formation stimulated by 1,25 dihydroxyvitamin D3. Further, conditioned media from marrow cultures exposed to rhIL-6 contained elevated levels of IL-1 beta (500 pg/ml compared to 23 pg/ml in control cultures 15 h after IL-6 addition). These results suggest that the capacity of rhIL-6 to stimulate formation of MNC which cross-react with 23c6 is mediated by induction of release of IL-1 beta. 相似文献
56.
The Large Isoform of Myelin-Associated Glycoprotein Is Scarcely Expressed in the Quaking Mouse Brain
Nobuya Fujita Shuzo Sato Hideaki Ishiguro Takashi Inuzuka Hiroko Baba Tadashi Kurihara Yasuo Takahashi Tadashi Miyatake 《Journal of neurochemistry》1990,55(3):1056-1059
Two polypeptide isoforms of myelin-associated glycoprotein (MAG) with molecular masses of 72 and 67 kDa are produced by alternative splicing of the exon 12 portion. Our previous work has demonstrated that in the quaking mouse brain this alternative splicing is lacking and that the mRNA coding the large MAG isoform (L-MAG) is scarcely expressed, whereas that of small MAG isoform (S-MAG) is overexpressed. In the present study, we prepared antisera specific to the S-MAG and L-MAG amino acid residues, respectively. Immunoblots showed that the L-MAG band was scarcely detectable in the quaking mouse brain, whereas the S-MAG band had an apparently higher molecular mass than in the normal control. Our immunohistochemical study also showed that L-MAG was scarcely stained in the quaking mouse brain. These results seemed to reflect a reduction in content of L-MAG mRNA and abnormal glycosylation in the quaking mouse brain. 相似文献
57.
58.
Interconversion of polyamines in wild-type strains and mutants of yeasts and the effects of polyamines on their growth 总被引:1,自引:0,他引:1
Koei Hamana Shigeru Matsuzaki Kohei Hosaka Satoshi Yamashita 《FEMS microbiology letters》1989,61(1-2):231-236
Yeasts of wild-type strains, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe and Candida albicans were shown to have the ability to form aminopropylcadaverine and aminopropylhomospermidine from cadaverine and homospermidine, respectively. A polyamine autotroph S. cerevisiae 179-5, which lacks ornithine decarboxylase, produced both aminopropylcadaverine and aminopropylhomospermidine, while another mutant S. cerevisiae Y 260 A, which lacks spermine synthase, formed only aminopropylcadaverine. Naturally-occurring triamines and tetraamines except norspermidine and norspermine stimulated the growth of S. cerevisiae 179-5. All the six aliphatic diamines with carbon chain length ranging from one to six were effective in activating the growth of S. cerevisiae 179-5, though all of them were not converted to either triamines or tetraamines. 相似文献
59.
Acetoacetyl-CoA thiolase (Thiolase I) and 3-ketoacyl-CoA thiolase (Thiolase III) found in peroxisomes of an n-alkane-utilizing yeast, Candida tropicalis pK 233, were each purified to homogeneity by successive column chromatographies. Thiolase I was composed of six identical subunits whose molecular masses were 41,000 Da, and Thiolase III was a homodimer composed of 43,000 Da subunits. The results of limited proteolysis of the respective thiolases indicated that they were quite different in peptide components. Furthermore, these enzymes were immunochemically distinguishable. The kinetic studies showed that the substrates with long chains were degraded exclusively by Thiolase III, while acetoacetyl-CoA was degraded preferentially by Thiolase I. Thus, in the yeast, the complete degradation of fatty acids is suggested to be carried out efficiently in peroxisomes. 相似文献
60.
Naoto Ohnishi Hiroaki Kodania Satoshi Ando Atsushi Komamine 《Physiologia plantarum》1990,80(1):95-101
The effects of inhibition of the synthesis of protein, mRNA or rRNA on the progression of the cell cycle have been analyzed in cultures of Catharanthus roseus in which cells were induced to divide in synchrony by the double phosphate starvation method. The partial inhibition of protein synthesis at the G1 phase by anisoniycio or cycloheximide caused the arrest of cells in the G1 phase or delayed the entry of cells into the S phase. When protein synthesis was partially inhibited at the S phase, cell division occurred to about the same extent as in the control. When asynchronously dividing cells were treated with cycloheximide, cells accumulated in the G1 phase, as shown by flow-cytometric analysis. The partial inhibition of mRNA synthesis by α-amanitin at the G1 phase caused the arrest of cells in the G1 phase, although partial inhibition of mRNA synthesis at the S phase had little effect on cell division. In the case of inhibition of synthesis of rRNA by actinomycin D at the G1 phase, initiation of DNA synthesis was observed, but no subsequent DNA synthesis or the division of cells occurred. However, the addition of actinomycin D during the S phase had no effect on cell division. These results suggest that specific protein(s), required for the progression of the cell cycle, are synthesized in the G1 phase, and that the mRNA(s) that encode these proteins are also synthesized at the G1 phase. 相似文献