Identification of angiotensin I-converting enzyme inhibitory peptides derived from salmon muscle and their antihypertensive effect     

Hiroyuki Enari  Yoshinori Takahashi  Masataka Kawarasaki  Motohiko Tada  Kuniaki Tatsuta 《Fisheries Science》2008,74(4):911-920

ABSTRACT:   The salmon peptide digested from salmon muscle showed a strong inhibitory activity against the angiotensin I-converting enzyme (ACE). The antihypertensive effect of the salmon peptide on spontaneously hypertensive rats (SHR) was examined. After the single intravenous administration of the salmon peptide at a dose of 30 mg/kg body weight, the systolic blood pressure (SBP) was significantly reduced against the control. Further, a double-blind, placebo-controlled, parallel-group study determined the efficacy of the salmon peptide in mild hypertensive subjects. The SBP, after a 1.0 g of salmon peptide intake, was significantly reduced at 4 weeks after the intake, and 2 weeks after the intake finished, compared to the value before ingestion. Bioassay-guided separation of the salmon peptide, using a combination of column chromatographic techniques, led to the identification of 20 active di- and tri-peptides, including Ile-Val-Phe and Phe-Ile-Ala as two new ACE inhibitory tripeptides. Ile-Trp had the strongest ACE inhibitory activity (IC₅₀ = 1.2 μM) in vitro , and contributed 5.2% to the total ACE inhibitory activity. The salmon peptide and Ile-Trp showed a digestive resistance by in vitro assay, which mimicked the digestive organ, and had no affinity for factors related to blood pressure regulation, except for the ACE inhibitory activity.  相似文献   

Comparative studies on the photosynthesis of higher plants     

Hideo Imai  Masataka Fukuyama  Yoshio Yamada 《Soil Science and Plant Nutrition》2013,59(3):253-261

The rate of sugar formation from aspartate-¹⁴C(U) and alanine-L-¹⁴C was examined under various light intensities in three C₄-plants. The results obtained were as follows.

The rates of sugar formation from aspartate-¹⁴C(U) became larger in the following order, Paspalum urvillei, Egragrostis ferrunginea, and Zoysia japonica. This order agreed well with the order of their photosynthetic rates measured by gas analyzer. In all the C₄-plants, there were three steps in the sugar formation curve from aspartate-¹⁴C(U). At first, sugar linearly increased with an increase in the light intensity up to 20 klux. Second, from 20 to 40 klux, it hardly increased with an increase in the light intensity. Third, above 40 klux, it increased linearly again. On the other hand, the plateau did not exist between 20 and 40 klux in the sugar formation curves from alanine-l-¹⁴C in any of the cases, and sugar continued to increase with an increase in the light intensity up to 80 klux.

At low light intensities, the amount of CO₂ released from aspartate-¹⁴C(U) and alanine-l-¹⁴C correlated well with the magnitude of the dark respiration in the C₄-plants. At a high light intensity, however, CO₂ release closely correlated with the thickness of mesophyll layers surrounding the vascular bundle sheath. The thicker the mesophyll layers were, the smaller the release of CO₂ became. From this evidence, we conclude that the mesophyll layers play a vital role in refixation of the internal CO₂ in the light.  相似文献   

Specific hydroxy fatty acids in royal jelly activate TRPA1     

Terada Y  Narukawa M  Watanabe T 《Journal of agricultural and food chemistry》2011,59(6):2627-2635

This is the first report of TRPA1 activation by fatty acids. Activation of TRPA1 and TRPV1 induces thermogenesis and energy expenditure enhancement. In this study, we searched for novel agonists of TRPA1 and TRPV1 from a nonpungent food, royal jelly (RJ). We measured the activation of human TRPA1 and TRPV1 by RJ extracts and found that the hexane extract contains TRPA1 agonists. The main functional compounds in the hexane extract were trans-10-hydroxy-2-decenoic acid (HDEA) and 10-hydroxydecanoic acid (HDAA). These are characteristic fatty acids of RJ. Their EC50 values were about 1,000 times larger than that of AITC, and their maximal responses were equal. They activated TRPA1 more strongly than TRPV1. Their EC50 values for TRPV1 were 2 times larger, and the maximal response was less than half of that for TRPA1. Next, we studied the potencies of other lipid components for both receptors. Most of them have higher affinity to TRPA1 than TRPV1. Among them, dicarboxylic acids showed equal efficacy for both receptors, but those are present in only small amounts in RJ. We concluded that the main function of RJ is TRPA1 activation by HDEA and HDAA, the major components of the RJ lipid fraction.  相似文献   

Effects of microbial growth on the preservation of scallop muscle in a vital state     

Ken-ichi?Kaneko  Masataka?Satomi  Meiko?Kimura  Hisanori?Nozawa  Nobuo?SekiEmail author 《Fisheries Science》2005,71(5):1167-1173

ABSTRACT:   Adductor muscles dissected from live scallop Patinopecten yessoensis were stored in oxygenated artificial sea water. The initial muscle adenosine triphosphate (ATP) level, approximately 7.5 µmol/g, remained longer at 5°C than at either 0 or 10°C. The pH of sea water decreased continuously and the consumption of dissolved oxygen increased even after muscle ATP was almost exhausted. The number of viable microbes, measured as colony-forming units (c.f.u.) in the muscle, increased to reach a plateau at approximately 10⁷−10⁸ c.f.u./g, while muscle ATP remained at high levels. After this time, muscle ATP sharply decreased. Antibiotics or sorbate added into the oxygenated sea water effectively inhibited both the growth of microbes and the decrease in the pH of sea water. Under these conditions, the retention period of muscle ATP was greatly extended. Thus, it seems most likely that scallop adductor muscle cells are suffocated by the limitation of oxygen supply caused by aerobic microbes grown on the surface of muscle tissue.  相似文献   

Effects of bistheonellide A,an Actin-polymerization Inhibitor,on Chinese Hamster V79 Cells and on IL-8 Production in PMA-stimulated HL-60 Cells     

Taiko Oda  Jinzhong Xu  Ayako Fujita  Masataka Mochizuki  Michio Namikoshi 《Marine drugs》2006,4(1):22-27

Bioassay-guided isolation from the ethanol extract of a marine sponge Theonella sp. collected in Palau yielded bistheonellide A, which strongly inhibited the colony formation of Chinese hamster V79 cells (EC₅₀ = 6.8 nM). Bistheonellide A is an actin-polymerization inhibitor and was suggested to control cytokine production. Therefore, we attempted to detect an effect of this compound on IL-8 production in PMA-stimulated HL-60 cells. Interestingly, bistheonellide A did not modulate the production of IL-8 under cytotoxic concentrations as determined by LDH analysis. Although the correlation between the inhibition of microtubule assembly and the stimulation of IL-8 production has been observed for several compounds, the polymerization of actin was not related to an IL-8 production in the case of bistheonellide A. It will be suggested that the actin polymerization is not involved in the IL-8 production system.  相似文献   

Effects of Lissoclibadins and Lissoclinotoxins,Isolated from a Tropical Ascidian Lissoclinum cf. badium,on IL-8 production in a PMA-stimulated Promyelocytic Leukemia Cell Line     

Taiko Oda  Takeshi Fujiwara  Hongwei Liu  Kazuyo Ukai  Remy E. P. Mangindaan  Masataka Mochizuki  Michio Namikoshi 《Marine drugs》2006,4(1):15-21

The effects of seven compounds 1–7, isolated from a tropical ascidian Lissoclinum cf. badium, on IL-8 production in PMA-stimulated HL-60 cells were examined. Lissoclibadins 2 (2) and 3 (3) and lissoclinotoxin F (5) increased the IL-8 production in a dose-dependent manner. Compounds 2 and 5 are structural isomers possessing dimeric structures of trans and cis-orientations, respectively, and showed a very similar activity on the induction of IL-8 levels. Compound 3 and lissoclinotoxin E (4) are also structural isomers having dimeric trans and cis-structures, respectively, but 4 did not induce the IL-8 production. Lissoclibadin 1 (1, trimeric compound) and two monomeric compounds (6 and 7) did not increase the IL-8 level. Therefore, the differences in their structures remarkably affected the IL-8 production activity, the inhibition of cell proliferation, and the survival of HL-60 cells. Lissoclibadin 2 was the most interesting compound of the seven metabolites tested in this study.  相似文献   

Relation between tacticity and fiber diameter in melt-electrospinning of polypropylene     

Yosuke Kadomae  Yasuhide Maruyama  Masataka Sugimoto  Takashi Taniguchi  Kiyohito Koyama 《Fibers and Polymers》2009,10(3):275-279

Electrospun atactic polypropylene (PP) fibers are thicker than those obtained from isotactic PP, although the viscosity of molten PPs is almost same. Thus we focused on the effect of tacticity of PP on fiber diameters. The PP samples with various tacticity were prepared by changing the blend ratio of isotactic PP and atactic PP. Melt-electrospinning is performed by using blended samples, and then electrospun fibers were observed by scanning electron microscope to evaluate fiber diameter of obtained fibers. It is clear that the diameter of electrospun PP fibers decreases as high tacticity content of PP increases. This result suggests that tacticity of samples is an important factor to control the electrospun fiber diameter.  相似文献   

Vitamin A Deprivation Affects the Progression of the Spermatogenic Wave and Initial Formation of the Blood-testis Barrier,Resulting in Irreversible Testicular Degeneration in Mice     

Masataka CHIHARA  Saori OTSUKA  Osamu ICHII  Yasuhiro KON 《The Journal of reproduction and development》2013,59(6):525-535

The blood testis-barrier (BTB) is essential for maintaining homeostasis in the seminiferous epithelium. Although many studies have reported that vitamin A (VA) is required for the maintenance of spermatogenesis, the relationships between the BTB, spermatogenesis and VA have not been elucidated. In this study, we analyzed BTB assembly and spermatogenesis in the testes of mice fed the VA-deficient (VAD) diet from the prepubertal period to adulthood. During the prepubertal period, no changes were observed in the initiation and progression of the first spermatogenic wave in mice fed the VAD diet. However, the numbers of preleptotene/leptotene spermatocytes derived from the second spermatogenic wave onwards were decreased, and initial BTB formation was also delayed, as evidenced by the decreased expression of mRNAs encoding BTB components and VA signaling molecules. From 60 days postpartum, mice fed the VAD diet exhibited apoptosis of germ cells, arrest of meiosis, disruption of the BTB, and dramatically decreased testis size. Furthermore, vacuolization and calcification were observed in the seminiferous epithelium of adult mice fed the VAD diet. Re-initiation of spermatogenesis by VA replenishment in adult mice fed the VAD diet rescued BTB assembly after when the second spermatogenic wave initiated from the arrested spermatogonia reached the preleptotene/leptotene spermatocytes. These results suggested that BTB integrity was regulated by VA metabolism with meiotic progression and that the impermeable BTB was required for persistent spermatogenesis rather than meiotic initiation. In conclusion, consumption of the VAD diet led to critical defects in spermatogenesis progression and altered the dynamics of BTB assembly.  相似文献   

Pathogenic diversity of Phytophthora sojae and breeding strategies to develop Phytophthora-resistant soybeans     

Takuma Sugimoto  Masayasu Kato  Shinya Yoshida  Isao Matsumoto  Tamotsu Kobayashi  Akito Kaga  Makita Hajika  Ryo Yamamoto  Kazuhiko Watanabe  Masataka Aino  Toru Matoh  David R. Walker  Alan R. Biggs  Masao Ishimoto 《Breeding Science》2012,61(5):511-522

Phytophthora stem and root rot, caused by Phytophthora sojae, is one of the most destructive diseases of soybean [Glycine max (L.) Merr.], and the incidence of this disease has been increasing in several soybean-producing areas around the world. This presents serious limitations for soybean production, with yield losses from 4 to 100%. The most effective method to reduce damage would be to grow Phytophthora-resistant soybean cultivars, and two types of host resistance have been described. Race-specific resistance conditioned by single dominant Rps (“resistance to Phytophthora sojae”) genes and quantitatively inherited partial resistance conferred by multiple genes could both provide protection from the pathogen. Molecular markers linked to Rps genes or quantitative trait loci (QTLs) underlying partial resistance have been identified on several molecular linkage groups corresponding to chromosomes. These markers can be used to screen for Phytophthora-resistant plants rapidly and efficiently, and to combine multiple resistance genes in the same background. This paper reviews what is currently known about pathogenic races of P. sojae in the USA and Japan, selection of sources of Rps genes or minor genes providing partial resistance, and the current state and future scope of breeding Phytophthora-resistant soybean cultivars.  相似文献   

Acidic soil conditions suppress zoospore release from zoosporangia in <Emphasis Type="Italic">Olpidium virulentus</Emphasis>     

Yutaka Iwamoto  Kai Inoue  Shinji Nishiguchi  Katsunari Matsuura  Masataka Aino  Hitoshi Nakayashiki  Kenichi Ikeda 《Journal of General Plant Pathology》2017,83(4):240-243

Lettuce big-vein disease, caused by Mirafiori lettuce big-vein virus and Lettuce big-vein associated virus, is suppressed when the pH of field soil becomes acidic. Therefore, we evaluated the effect of soil pH on the activities of Olpidium virulentus, the vector of the viruses. We found that acidic soil, pH less than 6.0, significantly reduced O. virulentus infection of the root and influenced the detection rate of zoospores released in the surrounding water. We concluded that acidic soil suppresses zoospore release from zoosporangia.  相似文献