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161.
Yoneda M Goto M Nakamura K Yokohama S Kono T Tanamo M Shimada T Hiraishi H 《Regulatory peptides》2005,131(1-3):74-81
Central administration of thyrotropin-releasing hormone (TRH) enhanced pancreatic blood flow in animal models. TRH nerve fibers and receptors are localized in the dorsal vagal complex (DVC), and retrograde tracing techniques have shown that pancreatic vagal nerves arise from the DVC. However, nothing is known about the central sites of action for TRH to elicit the stimulation of pancreatic blood flow. Effect of microinjection of a TRH analog into the DVC on pancreatic blood flow was investigated in urethane-anesthetized rats. After measuring basal flow, a stable TRH analog (RX-77368) was microinjected into the DVC and pancreatic blood flow response was observed for 120 min by laser Doppler flowmetry. Vagotomy of the several portions, or pretreatment with atoropine methyl nitrate or N(G)-nitro-l-arginine-methyl ester was performed. Microinjection of RX-77368 (0.1-10 ng) into the left or right DVC dose-dependently increased pancreatic blood flow. The stimulation of pancreatic blood flow by RX-77368 microinjection was eliminated by the same side of cervical vagotomy as the microinjection site or subdiaphragmatic vagotomy, but not by the other side of cervical vagotomy. The TRH-induced stimulation of pancreatic blood flow was abolished by atropine or N(G)-nitro-l-arginine-methyl ester. These results suggest that TRH acts in the DVC to stimulate pancreatic blood flow through vagal-cholinergic and nitric oxide dependent pathways, indicating that neuropeptides may act in the specific brain nuclei to regulate pancreatic function. 相似文献
162.
Mizuno K Sawa M Harada H Taoka I Yamashita H Oue M Tsujiuchi H Arai Y Suzuki S Furutani Y Kato S 《Bioorganic & medicinal chemistry》2005,13(3):855-868
The synthesis and evaluation of a novel series of 1,7-cyclized indole-based human adrenergic receptor (beta3-AR) agonists are reported. The synthesis of a variety of 1,7-cyclized indole part was accomplished by the Mitsunobu reaction or a ring closing metathesis (RCM) reaction. SAR studies revealed that expansion of the ring size resulted in considerable selectivity against the beta1- and beta2-ARs. Compound 26, an eight-membered ring analogue with a double bond on its 1,7-linker portion, was found to be a potent beta3-AR agonist (EC50 = 0.75 nM, IA = 90%) with extremely high selectivity for the beta3-AR over the beta1- and beta2-ARs. 相似文献
163.
Shiro?Mori Yukiko?Adachi Sakae?Horimoto Sakae?Suzuki Masaru?NakanoEmail author 《In vitro cellular & developmental biology. Plant》2005,41(6):783-788
Summary In researching the application of genetic transformation to lily breeding, callus formation from cultured explants and plant
regeneration from induced calluses were examined in 33 Lilium genotypes, 21 species, three Asiatic hybrids, two LA hybrids, two Longiflorum hybrids, three Oriental hybrids, and two Trumpet
hybrids. Seed, bulb scale, leaf, or filament explants were placed on a medium containing 4.1 μM 4-amino-3,5,6-trichloropicolinic acid (picloram; PIC) and cultured in the dark. After 2 mo., callus formation was observed
in 30 genotypes, and a formation frequency of more than 50% was obtained in 24 genotypes. Bulb scale and filament explants
showed great ability to form calluses, whereas seeds had poor ability. Most of the induced calluses were yellow and had a
nodular appearance. When subcultured onto the same fresh medium, twofold or more increases in callus mass were obtained in
1 mo. for 15 genotypes. Callus lines showing sustained growth 1 yr after the initiation of subculture were examined for their
ability to produce shoots on a medium without plant growth regulators (PGRs) and a medium containing 22 μM 6-benzyladenine (BA). Shoot regeneration was observed in all genotypes examined, and a regeneration frequency of over 80%
was obtained in 20 genotypes. Initial explants used for callus induction and callus type (nodular or friable) had no effect
on shoot regeneration. Most of the regenerated shoots developed into complete plantlets following their transfer to a PGR-free
medium. 相似文献
164.
Isolation and Expression Profiling of Genes Upregulated in the Peripheral Blood Cells of Systemic Lupus Erythematosus Patients 总被引:3,自引:0,他引:3
165.
Sawa M Mizuno K Harada H Tateishi H Arai Y Suzuki S Oue M Tsujiuchi H Furutani Y Kato S 《Bioorganic & medicinal chemistry letters》2005,15(4):1061-1064
The continued SAR investigation of tryptamine-based human beta(3)-adrenergic receptor (AR) agonists is reported. Prior efforts resulted in the identification of 2 as a potent beta(3)-AR agonist. Further modification of the left side arylsulfonamide portion in 2 provided compounds with good cell permeability, which have potent agonistic activity for beta(3)-AR. Cinnamylamine analog 16i exhibited an excellent agonistic profile in vitro and good oral bioavailability in rats. 相似文献
166.
OCA4: evidence for a founder effect for the p.D157N mutation of the MATP gene in Japanese and Korean
Inagaki K Suzuki T Ito S Suzuki N Fukai K Horiuchi T Tanaka T Manabe E Tomita Y 《Pigment cell research / sponsored by the European Society for Pigment Cell Research and the International Pigment Cell Society》2005,18(5):385-388
Oculocutaneous albinism type 4 (OCA4) was identified as a rare form of human OCA among a group of autosomal recessive hypopigmentary disorders. Little is known about the prevailing distribution of patients of OCA4 with mutations of the MATP gene, although one Turkish, five German, one Korean, and 18 Japanese patients have been reported so far. The p.D157N mutation was previously reported to be the most frequent (0.389; 14/36) in Japanese patients and was also found in a Korean patient. On the other hand, this mutation has not been found in Turkish and German patients. We therefore investigated haplotypes of the patients who have the p.D157N mutation. The results showed that OCA4 is prevalent in East Asia including Japan and Korea likely as a result of a founder effect for the p.D157N mutation. Furthermore, it is suspected that the p.D157N mutation might have occurred on an ancestral chromosome after the divergence of Orientals and Caucasians. 相似文献
167.
This paper reports the synthesis of hyaluronan (HA) and its derivatives via the hyaluronidase-catalyzed polymerization of 2-substituted oxazoline derivative monomers designed as "transition-state analogue substrates". Polymerization of 2-methyl oxazoline monomer from N-acetylhyalobiuronate (GlcAbeta(1-->3)GlcNAc) effectively proceeded at pH 7.5 and 30 degrees C, giving rise to synthetic HA (natural type) in an optimal yield of 78% via ring-opening polyaddition under total control of regioselectivity and stereochemistry. Hyaluronidase catalysis enabled the polymerization of 2-ethyl, 2-n-propyl, and 2-vinyl monomers, affording the corresponding HA derivatives (unnatural type) with N-propionyl, N-butyryl, and N-acryloyl functional groups, respectively, at the C2 position of all glucosamine units in good yields. The 2-isopropyl oxazoline derivative provided the N-isobutyryl derivative of HA in low yields. Monomers of 2-phenyl and 2-isopropenyl oxazoline derivatives were not polymerized. The mechanism of the polymerization is discussed. 相似文献
168.
Identification of three isoforms for mitochondrial adenine nucleotide translocator in the pufferfish Takifugu rubripes 总被引:1,自引:0,他引:1
Three adenine nucleotide translocator (ANT) genes were identified through in silico data mining of the Fugu genome database along with isolation of their corresponding cDNAs in vivo from the pufferfish (Takifugu rubripes). As a result of phylogenetic analysis, the ANT gene on scaffold_254 corresponded to mammalian ANT1, whereas both of those on scaffold_6 and scaffold_598 to mammalian ANT3. The ANT gene encoded by scaffold_6 was expressed ubiquitously in various tissues, whereas the ANT genes encoded by scaffold_254 and scaffold_598 were predominantly expressed in skeletal muscle and heart, respectively. 相似文献
169.
The bis(alpha-D-mannopyranosyl)-[60]fullerene conjugate 3 was prepared by thermal coupling of C60 and either 2-azidoethyl 2,3,4,6-tetra-O-acetyl- or 2,3;4,6-di-O-isopropylidene-alpha-D-mannopyranoside (Scheme). Compound 3 was found to readily self-assemble. Dynamic-light-scattering (DLS) and atomic-force microscopy (AFM) experiments supported that the amphiphilic compound gives rise to nano-sized supramolecular structures during sugar deprotection (Ac-group removal) performed in MeOH/CH2Cl2 solution. Encapsulation studies with an aqueous suspension of 3 showed that the self-assembling structure envelopes Ba2+ and the fluorescent dye Acridine Red during its formation, which indicates that it resembles a bilayer vesicle or an unadulterated liposome with an inner hollow space. In addition to this notable property, the unique molecular geometry of the spatially arranged mannosyl surface residues of 3 gives rise to strong binding of the carbohydrate-recognizing lectin Con A. Hence, the polar amphiphilic end of 3 mimics the structure of 3,6-branched tri-alpha-D-mannoside (6; Fig. 3), a natural ligand of the Con A protein. 相似文献
170.
Kobayashi K Yoshioka S Kato Y Asano Y Aono S 《The Journal of biological chemistry》2005,280(7):5486-5490
Phenylacetaldoxime dehydratase from Bacillus sp. strain OxB-1 (OxdB) catalyzes the dehydration of Z-phenylacetaldoxime (PAOx) to produce phenylacetonitrile. OxdB contains a protoheme that works as the active center of the dehydration reaction. The enzymatic activity of ferrous OxdB was 1150-fold higher than that of ferric OxdB, indicating that the ferrous heme was the active state in OxdB catalysis. Although ferric OxdB was inactive, the substrate was bound to the ferric heme iron. Electron paramagnetic resonance spectroscopy revealed that the oxygen atom of PAOx was bound to the ferric heme, whereas PAOx was bound to the ferrous heme in OxdB via the nitrogen atom of PAOx. These results show a novel mechanism by which the activity of a heme enzyme is regulated; that is, the oxidation state of the heme controls the coordination structure of a substrate-heme complex, which regulates enzymatic activity. Rapid scanning spectroscopy using stopped-flow apparatus revealed that a reaction intermediate (the PAOx-ferrous OxdB complex) showed Soret, alpha, and beta bands at 415, 555, and 524 nM, respectively. The formation of this intermediate complex was very fast, finishing within the dead time of the stopped-flow mixer (approximately 3 ms). Site-directed mutagenesis revealed that His-306 was the catalytic residue responsible for assisting the elimination of the hydrogen atom of PAOx. The pH dependence of OxdB activity suggested that another amino acid residue that assists the elimination of the OH group of PAOx would work as a catalytic residue along with His-306. 相似文献