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991.
Yoshio Ikeda Kazuwa Nakao Takaaki Yoshimasa Noboru Yanaihara Shosaku Numa Hiroo Imura 《Biochemical and biophysical research communications》1982,107(2):656-662
High performance liquid chromatography (HPLC) coupled with specific radioimmunoassays for methionine-enkephalin-Arg6-Gly7-Leu8 (Met-E-Arg6-Gly7-Leu8), methionine-enkephalin (Met-E), leucine-enkephalin (Leu-E) and methionine-enkephalin-Arg6-Phe7 (Met-E-Arg6-Phe7) has demonstrated that Met-E-Arg6-Gly7-Leu8 exists together with Met-E, Leu-E and Met-E-Arg6-Phe7 in the brain of guinea pig, rat and golden hamster. The content of Met-E-Arg6-Gly7-Leu8 was comparable to those of Leu-E and Met-E-Arg6-Phe7, whereas that of Met-E was the highest among the four opioid peptides. These results are compatible with the recent studies on the nucleotide sequence of cloned cDNA for preproenkephalin from bovine adrenal medulla, which reveal that this precursor molecule contains four copies of Met-E and one copy each of Leu-E, Met-E-Arg6-Phe7 and Met-E-Arg6-Gly7-Leu8. The co-existence of Met-E-Arg6-Gly7-Leu8 with Met-E, Leu-E and Met-E-Arg6-Phe7 suggests that their biosynthetic pathway in the brain is similar to that in the adrenal medulla. 相似文献
992.
Susumu Seino Hideo Sakurai Hideshi Kuzuya Kinsuke Tsuda Keiichiro Tanigawa Kiyoyuki Takahashi Yutaka Seino Hiroo Imura 《Peptides》1982,3(2):175-182
In order to elucidate the effect of glucagon antiserum on the endocrine pancreas, the release of somatostatin, glucagon, and insulin from the isolated perfused rat pancreas was studied following the infusion of arginine both with and without pretreatment by glucagon antiserum. Various concentrations of arginine in the presence of 5.5 mM glucose stimulated both somatostatin and glucagon secretion. However, the responses of somatostatin and glucagon were different at different doses of arginine. The infusion of glucagon antiserum strongly stimulated basal secretion in the perfusate total glucagon (free + antibody bound glucagon) and also enhanced its response to arginine, but free glucagon was undetectable in the perfusate during the infusion. On the other hand, the glucagon antiserum had no significant effect on either insulin or somatostatin secretion. Moreover, electron microscopic study revealed degrannulation and vacuolization in the cytoplasm of the A cells after exposure to glucagon antiserum, suggesting a hypersecretion of glucagon, but no significant change was found in the B cells or the D cells. We conclude that in a single pass perfusion system glucagon antiserum does not affect somatostatin or insulin secretion, although it enhances glucagon secretion. 相似文献
993.
994.
Mercury resistance of Clostridium cochlearium T-2P was found to be controlled by a different mechanism from those reported so far since no mercury-reducing activity was
detected in this strain.
The H2S generating ability as well as the demethylating activity of this bacterium was eliminated by the treatment with acridine
dye and recovered by the conjugation of the cured strain with the parent strain. In addition, the strain which lost their
abilities to generate H2S and to decompose methylmercury, showed higher sensitivity to mercurials than the parent strain. From these results, the
genes conferring both the activities seemed to reside on the plasmid and the mechanism of mercury resistance was probably
based on a detoxification mechanism involving methylmercury decomposition and inactivation of the inorganic mercury with H2S. 相似文献
995.
Identification of the mRNA coding for the ACTH-beta-lipotropin precursor in a human ectopic ACTH-producing tumor 总被引:5,自引:0,他引:5
T Tsukada Y Nakai H Jingami H Imura S Taii S Nakanishi S Numa 《Biochemical and biophysical research communications》1981,98(2):535-540
The mRNA coding for the ACTH-β-lipotropin precursor from a human ectopic ACTH-producing thymic carcinoid was identified by blot hybridization analysis with the bovine cDNA as a probe. The mRNA from the tumor had the same length (approximately 1,100 nucleotides) as that from the human pituitary. An additional hybridization-positive RNA species of a larger size was found in the tumor. Cell-free translation of the mRNA from the tumor as well as from the pituitary yielded a product with an apparent molecular weight of 38,000 that was reactive both with antibody to ACTH and with antibody to β-endorphin. 相似文献
996.
Fumiko Kinoshita Yoshikatsu Nakai Hideki Katakami Yuzuru Kato Haruaki Yajima Hiroo Imura 《Life sciences》1980,27(10):843-846
The effect of intraventricular administration of β-endorphin on pulsatile LH release in castrated conscious rats was studied. The administration of 1 μg of β-endorphin into the lateral ventricle inhibited pulsatile discharge of LH secretion. Intravenous administration of naloxone blocked the suppressive effect of β-endorphin on LH release. These results suggest a possible role of β-endorphin, in addition to Met5-enkephalin, in the control of LH release in male rats. 相似文献
997.
Tsutomu Watanabe Masayuki Yokozawa† Seita Emori ‡ Kumiko Takata‡ Akihiro Sumida§ Toshihiko Hara§ 《Global Change Biology》2004,10(6):963-982
This paper describes a Multilayered Integrated Numerical Model of Surface Physics – Growing Plants Interaction (MINoSGI), which represents interactions between the dynamics of forest ecosystems and microclimate. Aiming at a large‐scale study in the future, we describe forest dynamics by using area‐averaged prognostic equations for thedistributions of plant density and plant weight with respect to plant height classes, instead of individual‐based treatments for small‐scale forest patches. Growth and mortality of plants are modelled based on the carbon balance of each plant height class. The area‐averaged microclimate (e.g., light, wind speed, temperature, humidity, CO2 concentration) within the forest canopy is simulated by a one‐dimensional multilayer canopy model, which includes most of the physical and physiological processes that control the forest microclimate. Owing to its multilayered framework, a direct specification is possible for the difference in the growing environment among plants of different size and species. Given hourly meteorological conditions, the model outputs energy, water, CO2 and momentum fluxes to and from a forest, of which the structure changes through competition among plants. The model's performance was tested by comparing its outputs with observed data on the development of plant size distribution taken over a 5‐year period in an evergreen coniferous (Cryptomeria japonica) forest. The model produced realistic estimates of the total biomass increments during the period. The ratio of net primary production to gross primary production (=0.45) was consistent with previous estimates for temperate forests. The bimodal seasonal pattern in net ecosystem production was similar to the seasonal trend in the CO2 flux measured over a forest of the same species. Although some limitations due to the one‐dimensional representation of microclimate were noticeable, the model adequately simulated distributions of annual growth rate, plant weight and diameter across plant height classes. Since the basic equations can be extended to include the effect of spatial variability with marginal increase of computational costs, the present model framework is feasible for large‐scale studies. 相似文献
998.
Immunoreactive growth hormone (GH) secretion by human lymphocytes: augmented release by exogenous GH 总被引:2,自引:0,他引:2
N Hattori A Shimatsu M Sugita S Kumagai H Imura 《Biochemical and biophysical research communications》1990,168(2):396-401
Peripheral blood mononuclear cells (PBMCs) from normal adults secreted small amounts of human growth hormone (GH; 0.2-0.6 pg/10(5) cells/7 days culture) as measured by a highly sensitive enzyme immunoassay. Stimulation of PBMCs with phytohemagglutinin (PHA) consistently showed a 4-6 fold increase in GH secretion. Transformed B-lymphocytes by Epstein-Barr virus also secreted GH (0.8-4.8 pg/5 x 10(4) cells/7 days culture). GH secreted by lymphocytes comigrated with pituitary GH on an Ultrogel AcA44 column. Addition of GH during the culture augmented endogenous GH secretion from PHA-stimulated PBMCs. GH-releasing hormone and a somatostatin analogue, SMS 201-995, did not affect GH secretion from non-stimulated and PHA-stimulated PBMCs. These findings suggest that both T and B lymphocytes secrete immunoreactive GH in a different manner from that in the anterior pituitary. 相似文献
999.
Yasusi Yamamoto Akihiro Mizobuchi Hiroyuki Hiramatsu Yuzo Shioi 《Physiologia plantarum》1992,84(3):403-408
Development of chlorophyll-proteins in photosystem II was studied with Euglena gracilis Z. during dark-light transition. Upon illumination of the dark-grown cells, protochlorophyllide was photoconverted to chlorophyll(ide) a with a low efficiency (14%). After a lag time of 1-2 h, chlorophylls, apoproteins of antenna chlorophyll-protein complex CP 43/47 and of light-harvesting chlorophyll-protein complex (LHCII) accumulated in the thylakoid membrane in a coordinated fashion. There was, however, a significant difference in the stability between the newly formed LHCII and CP 43/47 judging from non-denaturing lithium dodecyl sulfate-polyacrylamide gel electrophoresis. The possibility that efficiencies of incorporation and stabilization of chlorophylls in the apoproteins differ among the chlorophyll-proteins in the early stage of greening of Euglena is discussed. 相似文献
1000.
K Miyahara T Kawamoto Y Mitsuuchi K Toda H Imura R D Gordon Y Shizuta 《Biochemical and biophysical research communications》1992,189(2):885-891
Glucocorticoid-suppressible hyperaldosteronism (GSH) is one variety of primary aldosteronism with hypertension and is inherited in an autosomal dominant mode. A recent report has indicated that GSH is caused by a gene duplication arising from unequal crossing over between the two genes, CYP11B1 and CYP11B2, encoding P-450(11 beta) and P-450C18, respectively (Lifton et al. Nature (1992) 355, 262-265). The nucleotide sequence analysis in the present study has demonstrated that unequal crossing over in the chimeric gene formed by the gene duplication occurs within the region from the 3'-portion of exon 4 through the 5'-portion of intron 4 in Australian GSH patients. Namely, the chimeric gene encodes a fused P-450 protein consisting of the amino-terminal side of P-450(11 beta) (encoded by exons 1-4 of CYP11B1) and the carboxyl-terminal side of P-450C18 (encoded by exons 5-9 of CYP11B2). When a cDNA corresponding to the chimeric gene is transfected into COS-7 cells, the fused P-450 protein expressed in the mitochondria exhibits steroid 18-hydroxylase or aldosterone synthase activity. These results provide the molecular genetic basis for the characteristic biochemical phenotype of GSH patients. 相似文献