Weak activity of UDP-glucuronosyltransferase toward Bisphenol analogs in mouse perinatal development     

Risa YABUSAKI  Hidetomo IWANO  Sumito TSUSHIMA  Nanako KOIKE  Naoko OHTANI  Kentaro TANEMURA  Hiroki INOUE  Hiroshi YOKOTA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(11):1479-1484

Bisphenol A (BPA) is a widely used industrial chemical that disrupts endocrine function. BPA is an endocrine disrupting chemical (EDC) that has been demonstrated to affect reproductive organ development, brain development, metabolic disease and post-natal behavior. Accordingly, Bisphenol analogs, Bisphenol F (BPF, bis (4-hydroxyphenyl) methane) and Bisphenol AF (BPAF, 4,4-hexafluoroisopropylidene) diphenol) are used as replacements for BPA. BPA is mainly metabolized by UDP-glucuronosyltransferase (UGT), UGT2B1, but this effective metabolizing system is weak in the fetus. In the present study, we demonstrated that hepatic UGT activity toward BPAF was very weak, in comparison with BPA and BPF, in the fetus, pups and dams. Conversely, hepatic UGT activity toward BPF was very weak in the fetus and newborn pups, and was increased to the same level as BPA post-partum. In conclusion, BPAF possibly tends to accumulate in the fetus, because of weak metabolism during the perinatal period, suggesting that the metabolism of individual Bisphenol analogs requires assessment to properly gauge their risks.  相似文献   

Effect of monensin withdrawal on rumen fermentation,methanogenesis and microbial populations in cattle          下载免费PDF全文

Arfan Abrar  Takamitsu Tsukahara  Makoto Kondo  Tomomi Ban‐Tokuda  Wang Chao  Hiroki Matsui 《Animal Science Journal》2015,86(9):849-854

This study was designed to obtain information on the residual influence of dietary monensin on ruminant fermentation, methanogenesis and bacterial population. Three ruminally cannulated crossbreed heifers (14 months old, 363 ± 11 kg) were fed Italian ryegrass straw and concentrate supplemented with monensin for 21 days before sampling. Rumen fluid samples were collected for analysis of short chain fatty acid (SCFA) profiles, monensin concentration, methanogens and rumen bacterial density. Post‐feeding rumen fluid was also collected to determine in vitro gas production. Monensin was eliminated from the rumen fluid within 3 days. The composition of SCFA varied after elimination of monensin, while total production of SCFA was 1.78 times higher than on the first day. Methane production increased 7 days after monensin administration ceased, whereas hydrogen production decreased. The methanogens and rumen bacterial copy numbers were unaffected by the withdrawal of monensin.  相似文献   

Evaluation of larval growth process and bamboo consumption of the bamboo powder-post beetle Dinoderus minutus using X-ray computed tomography     

Hiroki Watanabe  Yoshiyuki Yanase  Yoshihisa Fujii 《Journal of Wood Science》2015,61(2):171-177

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Oxidative stress inducers potentiate 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated pre-cardiac edema in larval zebrafish     

Katsuki TANAKA  Hikaru ADACHI  Hironobu AKASAKA  Junya TAMAOKI  Yuji FUSE  Makoto KOBAYASHI  Takio KITAZAWA  Hiroki TERAOKA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(7):1050

We reported the involvement of oxidative stress and prostaglandins including thromboxane and prostacyclin in pre-cardiac edema (early edema) caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). While the involvement of oxidative stress in TCDD-induced toxicity has been frequently reported, the mechanism of its action is still unclear. In the present study, oxidative stress inducers including paraquat, hydrogen peroxide (H₂O₂) and rotenone augmented early edema (edema) induced by a low concentration of TCDD (0.1 ppb) at 55 hr post fertilization (hpf), while each of them alone did not cause edema. Edema caused by TCDD plus oxidative stress inducers was almost abolished by antioxidants, an antagonist for thromboxane receptor (ICI-192,605) and an agonist for prostacyclin receptor (beraprost), suggesting that the site of action of these inducers was in the regular signaling pathway after activation of aryl hydrocarbon receptor type 2 (AHR2) by TCDD. Oxidative stress inducers also enhanced edema caused by an agonist for the thromboxane receptor (U46619), and the enhancement was also inhibited by antioxidants. Sulforaphane and auranofin, activators of Nrf2 that is a master regulator of anti-oxidative response, did not affect U46619-evoked edema but almost abolished TCDD-induced edema and potentiation by paraquat in both TCDD- and U46619-induced edema. Taken together, the results suggest that oxidative stress augments pre-cardiac edema caused by TCDD via activation of thromboxane receptor-mediated signaling in developing zebrafish. As paraquat and other oxidative stress inducers used also are environmental pollutants, interaction between dioxin-like compounds and exogenous source of oxidative stress should also be considered.  相似文献   

Histone H4 Modification During Mouse Spermatogenesis     

Yoshiki SHIRAKATA  Yuuki HIRADATE  Hiroki INOUE  Eimei SATO  Kentaro TANEMURA 《The Journal of reproduction and development》2014,60(5):383-387

The core histone is composed of four proteins (H2A, H2B, H3 and H4). Investigation of the modification patterns of histones is critical to understanding their roles in biological processes. Although histone modification is observed in multiple cells and tissues, little is known about its function in spermatogenesis. We focused on the modification patterns of histone H4 during murine spermatogenesis. We demonstrated that the individual N-terminal sites of H4 show different modification patterns during the differentiation of male germ cells. The methylation pattern varied depending on the residues that were mono-, di-, or tri-methylated. All the H4 modifications were high during the meiotic prophase, suggesting that histone H4 modification plays an important role during this stage of spermatogenesis. Elongating spermatids showed increased acetylation of histone H4, which may be associated with a histone-to-protamine substitution. Our results provide further insight into the specific relationship between histone H4 modification and gene expression during spermatogenesis, which could help to elucidate the epigenetic disorders underlying male infertility.  相似文献   

Expression of Krüppel-Like Factor 6, KLF6, in Rat Pituitary Stem/Progenitor Cells and Its Regulation of the PRRX2 Gene     

Hiroki UEHARU  Masashi HIGUCHI  Naoto NISHIMURA  Saishu YOSHIDA  Shiori SHIBUYA  Kenta SENSUI  Takako KATO  Yukio KATO 《The Journal of reproduction and development》2014,60(4):304-311

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Antimicrobial Susceptibility of Enterococcal Species Isolated from Antibiotic-Treated Dogs and Cats     

Yasushi KATAOKA  Yurie UMINO  Hiroki OCHI  Kazuki HARADA  Takuo SAWADA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(10):1399-1402

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Effect of improvement cutting on the community structure of aphyllophoraceous fungi on Okinawa Island     

Satoshi Yamashita  Tsutomu Hattori  Shin Abe  Hideaki Goto  Hiroki Sato 《Journal of Forest Research》2014,19(1):143-153

Improvement cutting, which decreases tree density by cutting and thinning while leaving logging residues, has been practiced on Okinawa Island since the 1970s and changes not only the vegetation composition but also the amount and composition of woody debris on the forest floor. To quantitatively compare the effect of improvement cutting with the effects of woody debris and vegetation on the community structure of aphyllophoraceous fungi, we conducted a field survey of vegetation composition, the amount and composition of woody debris, and the aphyllophoraceous fungi flora on Okinawa Island in December 2006. We established 3 plots in forest stands without logging and 13 plots in a forest that had undergone improvement cutting from 1 to 22 years before our field survey. The number and volume of woody debris tended to be highest soon after improvement cutting. We recorded 1,172 fungal samples belonging to 81 species in four orders. Fungal species richness was correlated with the composition of the woody debris. Fungal species composition in forest plots 1 year after improvement cutting differed from most of the other logged forests. Variation partitioning revealed that the effects of improvement cutting explained 14.1 % of the total variation in fungal species composition, and that differences in woody debris and vegetation not related to improvement cutting explained 40.4 %. Changes in the composition of woody debris caused by improvement cutting explained at most 2.7 % of the variation. This suggests that improvement cutting does not have a strong effect on fungal community structure, but woody debris does.  相似文献   

Treatment with an aromatase inhibitor induces complete sex change in the protogynous honeycomb grouper (Epinephelus merra)     

Ramji K. Bhandari  Mikihiko Higa  Hiroki Komuro  Shigeo Nakamura  Masaru Nakamura 《Fish physiology and biochemistry》2003,28(1-4):141-142

To study the mechanism of protogynous sex change in honeycomb grouper, the wild fish of both sexes and transitionals were collected for one year, and changes in gonadal structures and serum levels of sex hormones in each individual were examined. The onset of sex change was associated with low serum estradiol - 17β (E2) levels. In order to clarify whether E2 deprivation causes sex change, maturing females were implanted with the non-steroidal aromatase inhibitor (Fadrozole, AI). AI caused complete sex change from female to functional males in two and half months. The present results suggest that E2 is an important endogenous factor which regulates protogynous sex change in the honeycomb grouper.  相似文献   

Spatial-uniform application method of methane fermentation digested slurry with irrigation water in the rice paddy field     

Kozue Yuge  Hiroki Maeda  Munehiro Tanaka  Mitsumasa Anan  Yoshiyuki Shinogi 《Paddy and Water Environment》2014,12(3):335-342

Promoting biomass utilization, the objectives of this study were to clarify the spatial distribution of nitrogen, one of the most important fertilizer components in the methane fermentation digested slurry (i.e., the digested slurry), and to establish an effective method to apply spatial-uniformly digested slurry with irrigation water in the rice paddy field. A numerical model describing the unsteady two-dimensional flow and solution transport of paddy irrigation water was introduced. The accuracy of this model was verified with a field observation. The tendencies of the TN simulated in inlet and outlet portions had good agreement with the measured data and the accuracy of the numerical model could be verified. Using the numerical model, scenario analyses were conducted to determine the method for spatial-uniform application of the digested slurry with irrigation water. The simulated results indicated that drainage of the surface water and trenches at the soil surface were effective for spatial-uniform application of the digested slurry with irrigation water in the rice paddy fields. The effect of the trenches was maximized when the surface water of the rice paddy field was drained adequately.  相似文献