Physiological changes induced by salt intake in female Spontaneously Diabetic Torii‐Leprfa (SDT fatty) rat,a novel obese type 2 diabetic model     

Yoshiaki Katsuda  Yusuke Kemmochi  Mimi Maki  Ryuhei Sano  Yukihito Ishii  Katsuhiro Miyajima  Kochi Kakimoto  Takeshi Ohta 《Animal Science Journal》2014,85(5):588-594

Salt plays an important role in the control of blood pressure in obesity and diabetes mellitus. In this study, we investigated physiological changes such as blood pressure and renal function in salt‐loaded female Spontaneously Diabetic Torii‐Lepr^fa (SDT fatty) rats. SDT fatty rats were given 1% NaCl in drinking water for 14 weeks, from 4 to 18 weeks of age. Significant salt‐sensitive hypertension was observed in the salt‐loaded SDT fatty rats. Moreover, the salt‐loaded rats showed a decrease of creatinine clearance and deterioration on pathological renal findings, including glomerulosclerosis and tubular and interstitial lesions. Female SDT fatty rat is a useful model for investigating the mechanisms of high salt sensitivity in obesity and diabetes mellitus.  相似文献   

Expression profiles of perforin,granzyme B and granulysin genes during the estrous cycle and gestation in the bovine endometrium     

Tomokazu Ohta  Katsuo Koshi  Koichi Ushizawa  Misa Hosoe  Toru Takahashi  Takahiro Yamaguchi  Keiichiro Kizaki  Kazuyoshi Hashizume 《Animal Science Journal》2014,85(7):763-769

The conceptus is susceptible to destruction by maternal cytotoxic lymphocytes, which have cytotoxic potential. Therefore, it is expected that mechanisms for regulating cytotoxic lymphocytes exist, but little is known about the expression of cytotoxic genes in the endometrium. In the present study, we examined the spatial and temporal expression patterns of the cytotoxic genes perforin, granzyme B, and granulysin during the estrous cycle and gestation in the bovine endometrium. Endometrial tissues were collected from cows during the estrous cycle and gestation. The gene expression patterns of the three cytotoxic genes were examined using quantitative polymerase chain reaction and in situ hybridization, and cytotoxic lymphocyte subsets were characterized using immunohistochemistry. During mid‐ to late gestation in the intercaruncular (ICAR), granulysin expression was significantly increased, and a large number of granulysin‐expressing cells were localized in the luminal epithelium. Perforin and granzyme B displayed similar expression profiles and were highly expressed in the peri‐implantation endometrium, but few cells expressing these genes were found in the endometrial stroma. In conclusion, these findings suggest that in the ICAR epithelium granulysin may play important roles in the establishment and maintenance of gestation during normal pregnancy.  相似文献   

Serum thyroxine,estradiol-17β, and testosterone profiles during the parr-smolt transformation of masu salmon,Oncorhynchus masou     

Hideaki Yamada  Hiromi Ohta  Kohei Yamauchi 《Fish physiology and biochemistry》1993,12(1):1-9

Changes in serum thyroxine (T₄), estradiol-17β (E₂) and testosterone (T) levels during the parr-smolt transformation (smoltification) were investigated in the masu salmon (Oncorhynchus masou) in 1985 and 1987. T₄ showed a peak in levels at the early stage of smoltification and E₂ and T levels peaked almost at the same time. There were no significant differences between the concentrations of serum hormones in female and males. During smoltification, germ cells in the peri-nucleolus and spermatogonia stage were present in the ovary and testis, respectively. These results suggest that E₂ and T may be involved in smoltification in the masu salmon.  相似文献   

Effect of cross-sectional dimensions on bow and surface checking of sugi (Cryptomeria japonica) boxed-heart square timber dried by conventional kiln drying     

Kana Yamashita  Yasuhiko Hirakawa  Shuetsu Saito  Hiroshi Nakatani  Motoyoshi Ikeda  Masamitsu Ohta 《Journal of Wood Science》2014,60(1):1-11

The effect of cross-sectional dimensions on bow and surface checking were investigated, using the boxed-heart square timber of two sugi cultivars with dimensions 80, 120, and 140 mm and length 1.9 m taken at two different heights above the ground. The smaller cross-sectional timber tended to have larger bow, less surface checking, and larger dimensional shrinkage. However, the drying defects were different between the cultivars and sampling heights, depending on the shrinkage properties of the juvenile wood and the heartwood proportion in the core part of the stem. The bow was larger in the smaller cross-sectional timber in which the longitudinal shrinkage was large in the juvenile wood. Surface checking was more prominent in larger cross-sectional timber containing sapwood in its outer part, which suggested the surface checking was induced by drying stress, owing to large moisture gradients between the heartwood and sapwood. The cross-dimensional shrinkage of the timber was larger in timber with larger tangential shrinkage.  相似文献   

不同水肥条件下二倍体、四倍体和六倍体小麦养分吸收、利用效率的研究     

黄明丽  邓西平  周生路  赵玉宗 《作物学报》2007,33(5):708-716

试验选用了3个二倍体（Triticum boeoticum，AA；Aegilops speltoides，BB和Ae. tauschii，DD）、2个四倍体（T. dicoccoides，AABB和T. dicoccum，AABB）和1个六倍体（T. aestivum，AABBDD）的小麦进化材料，在不同水肥条件下研究小麦进化中养分效率的差异及水肥条件对小麦养分利用的影响。试验表明，随小麦的进化，养分（N、P和K）吸收量和吸收效率显著增加，但是籽粒养分含量却减少。水分胁迫和低肥处理减少小麦籽粒养分含量、（整株）养分吸收量和吸收效率。小麦的生物量养分利用效率和产量养分利用效率都存在显著的种间差异，而且后者的差异更大。随小麦的进化，生物量养分利用效率和产量养分利用效率均显著增加。6个小麦进化材料的生物量氮、磷利用效率（NUTEb和PUTEb）的大小顺序相同，均为：Ae. speltoides > T. dicoccum、T. dicoccoides、Ae. tauschii、T. boeoticum > T. aestivum，而生物量钾利用效率（KUTEb）是T. aestivum、Ae. tauschii、Ae. speltoides > T. dicoccoides > T. dicoccum > T. boeoticum。Ae. tauschii的产量养分利用效率显著高于其他两个二倍体小麦（AA和BB），表明D组染色体上存在有控制高效利用养分的基因。产量氮、磷、钾利用效率（NUTEg、PUTEg、KUTEg）和收获指数（HI）的大小排序均为：T. aestivum > T. dicoccum、T. dicoccoides、Ae. tauschii > T. boeoticum、Ae. speltoides。水分与养分对生物量养分利用效率有显著影响，而对产量养分利用效率的作用却不显著，说明小麦产量养分利用效率是较为稳定的特性，主要由基因型决定。水分胁迫有利于提高小麦生物量养分利用效率，但是增加施肥量却对其有负作用。  相似文献   

The electrical conductivity of post-perovskite in Earth's D' layer     

Ohta K  Onoda S  Hirose K  Sinmyo R  Shimizu K  Sata N  Ohishi Y  Yasuhara A 《Science (New York, N.Y.)》2008,320(5872):89-91

Recent discovery of a phase transition from perovskite to post-perovskite suggests that the physical properties of Earth's lowermost mantle, called the D' layer, may be different from those of the overlying mantle. We report that the electrical conductivity of (Mg0.9Fe0.1)SiO3 post-perovskite is >10(2) siemens per meter and does not vary greatly with temperature at the conditions of the D' layer. A post-perovskite layer above the core-mantle boundary would, by electromagnetic coupling, enhance the exchange of angular momentum between the fluid core and the solid mantle, which can explain the observed changes in the length of a day on decadal time scales. Heterogeneity in the conductivity of the lowermost mantle is likely to depend on changes in chemistry of the boundary region, not fluctuations in temperature.  相似文献   

Influence of delayed timing of owners' actions on the behaviors of their dogs,Canis familiaris     

Mariko Yamamoto  Takefumi Kikusui  Mitsuaki Ohta 《Journal of Veterinary Behavior: Clinical Applications and Research》2009,4(1):11-18

This study examined the influence of delayed actions from the owner, including commands, reinforcement, and punishment, on already-learned behaviors in 10 dogs. The delay times were set to 2.0, 1.0, 0.5, 0.27, and 0.13 seconds (s). Responses to commands with a delay (Delayed) were compared with those that were not delayed (Nondelayed). The results indicated that appropriate responses to commands decreased in 2.0, 1.0, and 0.5 s delayed conditions. As delay time increased, response to commands decreased. The numbers of commands used by handlers to make their dogs obey was significantly increased with a 2.0 and 1.0 second delay compared to the nondelayed trials. The time required for dogs to obey the commands was significantly increased in 2.0, 1.0, and 0.5 s delayed conditions compared to those of the nondelayed trials. There were no significant differences between the 0.27 s, 0.13 s, and the nondelayed condition. These results suggest that timing is an important factor affecting a dog's behavior not only while learning new things, but also in the production of learned desirable behaviors that could occur during everyday interactions.  相似文献   

Gonadotropins, gonadotropin receptors and their expressions during sexual maturation in yellowtail, a carangid fish     

M.A. Rahman  K. Ohta  A. Yamaguchi  H. Chuda  T. Hirai  M. Matsuyama 《Fish physiology and biochemistry》2003,28(1-4):81-83

To study the physiological roles of gonadotropins (GtHs) in the yellowtail, the cDNAs encoding each GtH subunit (GPHα, FSHβ and LHβ) and their receptors (FSHR and LHR) were isolated from the pituitary gland and gonads using the polymerase chain reaction (PCR). In addition, thyrotropin (TSH) and its receptor (TSHR) cDNAs, were isolated from the pituitary gland, ovary and testis. The changes in the mRNA levels of each subunit were determined at different stages of maturation. The isolated cDNAs of GPHα, FSHβ, LHβ and TSHβ were 662, 545, 595 and 879 bp long, respectively. The amino acid sequence identity of the yellowtail GPHα, FSHβ, LHβ and TSHβ subunits was 85–63, 68–33, 93–65 and 74–46%, respectively, as compared with other fish species. Northern blot analysis showed that GPHα and FSHβ were strongly expressed in pituitary at the early vitellogenic stage and during spermatogenesis, whereas LHβ was expressed significantly in the late vitellogenic stage, and in both spermatogenesis and spermiation. Full-length cDNAs encoding FSHR, LHR, and TSHR were obtained from the testes and ovaries. The FSHR, LHR and TSHR cDNA encoded a protein of 680, 702 and 778 amino acids, and showed the highest identity with tilapia FSHR (76%), tilapia LHR (84%) and striped bass TSHR (94%), respectively. Northern blot analyses indicated that all of these receptors are expressed differently at different stages in the ovaries and testes.  相似文献   

Occurrence and distribution during the post-settlement stage of two Choerodon species in shallow waters around Ishigaki Island, southern Japan     

Hideaki Yamada  Atsushi Nanami  Itaru Ohta  Kouki Fukuoka  Taku Sato  Masato Kobayashi  Narisato Hirai  Masayuki Chimura  Yuichi Akita  Yuuki Kawabata 《Fisheries Science》2012,78(4):809-818

The recruitment patterns of black-spot tuskfish Choerodon schoenleinii were compared with those of orange-dotted tuskfish (OT) C. ancholago. Individuals at the settlement and juvenile stages were collected using a push net in the intertidal zone and a seine net in seagrass beds. Relative values of standard length to total length (TL) for the two Choerodon species indicated an inflection point at approximately 10?C20?mm TL, suggesting that both species complete metamorphosis at a similar size. However, their temporal and spatial occurrence patterns were distinct. Newly settled individuals (postflexion stage) of black-spot tuskfish were collected mainly within foliage of Sargassum plants of the intertidal zone around March?CApril, while those of OT occurred in both the intertidal zone and seagrass beds mainly in May and June. In seagrass beds, the abundances of both species increased from May or June; however, the TL of black-spot tuskfish was bigger than that of OT. Therefore, black-spot tuskfish progressively migrate to seagrass beds after settling and completing metamorphosis in the intertidal zone, indicating that they utilize two different habitats as nursery grounds. Early spawning and migration from the intertidal zone by this species contributed to the occurrence of relatively large individuals in seagrass beds.  相似文献