ヘキサナール刺激でドーパミンを放出した PC12 細胞のドーパミンの再蓄積作用

　すべての食品に匂い（香り）がある．食品に含まれる匂い（香り）物質は，食品中の栄養素と同様に体内に取り込まれ，生理作用を示すと考えている． ヘキサナールは炭素数6 の直鎖アルデヒドであり，植物特有の新鮮な香りを構成している物質の1 つである． これまでに，私たちは，ヘキサナールがラット脳線条体切片及びラット副腎褐色細胞腫（PC12）細胞からのドーパミン放出を促進することを報告している． 　ドーパミンを放出した細胞は，次の刺激に応答するために，細胞内にドーパミンを再蓄積する必要がある． 本研究では，ヘキサナール刺激によりドーパミンを放出した PC12 細胞のドーパミン再蓄積について検討した． ヘキサナール刺激を受けた PC12 細胞内のドーパミン量は，1 時間で，刺激を受けていない細胞と同程度まで回復した． ドーパミンの再蓄積は，ノルアドレナリン及びセロトニン再取込み阻害薬であるイミプラミンにより阻害された． しかし，ドーパミンの前駆体であるチロシンによる有意な影響は検出されなかった．すなわち，ヘキサナール刺激後の PC12 細胞内へのドーパミンの再蓄積には，新たなドーパミン合成よりも，イミプラミンが作用するモノアミン輸送体による再取込みが関与することが示唆された． 生体においても，血流中のヘキサナール濃度が減少すれば，ドーパミンを放出した細胞内にドーパミンが再蓄積されると考えられる． 　All foods comprise odor compounds, which enter the body together with nutrients.　Odor compounds that enter the body may cause physiological effects. 　n-Hexanal (hexanal) is a straight-chain, six-carbon aldehyde that imparts a fresh plant flavor.　Previously, we reported that hexanal directly stimulates dopamine release from rat striatal slices or rat pheochromocytoma (PC12) cells.　These cells reaccumulate dopamine and then release it again in response to the next signal.　In the current investigation, I studied dopamine reaccumulation into PC12 cells that released dopamine after stimulation by hexanal.　PC12 cells were first stimulated with hexanal to release dopamine.　The extracellular fluid was then harvested, the dopamine concentration in the fluid was measured, and added to new Krebs-Ringers HEPES buffer (KRH) and incubated.　Dopamine was reaccumulated within 1 h by the PC12 cells immersed in the KRH.　Reaccumulation of dopamine was prevented by imipramine, a monoamine reuptake inhibitor in the extracellular fluid.　Tyrosine, a precursor of dopamine, did not have a significant effect on dopamine reaccumulation. 　Results of this study suggest that dopamine reuptake by monoamine transporters, rather than new dopamine synthesis, is responsible for dopamine reaccumulation into PC12 cells that had released dopamine in response to hexanal. 　Based on this research, I conclude that dopamine was released when the concentration of odor compounds in the blood reached a sufficient level and that dopamine reaccumulation into cells was triggered when the concentration of odor compounds in the blood decreased

A Study on the Clauses for the Container Trade Terms in the International Sales Contract : On the Container Trade Rules Agreement in a Certain Trade Association

来住哲二教授古稀記念特

Maxwell分布に基づく反応速度の温度依存性のシミュレーション

A particle kinetic energy probability distribution eqn. (5) is lead from Maxwell distribution. Based on the eqn. (5), the proportion of number of the molecules bearing kinetic energy above a certain activation energy is calculated by two methods, and is used to simulate the temperature dependence of chemical reaction rate. By performing numerical integration of the eqn. (5), it was possible to obtain the result with sufficient accuracy in the range where the activation energy is less than about 40 kJ/mol. However, it was difficult to obtain calculation result with enough precision in the region of activation energy of about 40 kJ/mol or more, from limitation of the time necessary for a calculation practically. Since the formula (5) is able to be approximated to exponential decay in the high energy region, it could be considered that it was appropriate to approximate the area on the right side of a certain threshold value x = a to the function value f(a) directly. This approximation gave satisfactory results qualitatively in the range of wide activation energy. In this method, it is unnecessary to perform repetitive processing to enlarge processing time, and it is only necessary to read the function value at once. Therefore, for any students, it is effective to examine various conditions while making trial and error

青葉山周辺から産する鉱物標本の産出層準－ 仙台地域の地学教材の基礎資料 －

Mineral specimens occurring around the Aobayama Hill have been utilized as scientific study objects, also as familiar geology-teaching materials in the Sendai area. We investigate the background geology of their occurrences including stratigraphic horizons, depositional conditions, and radiometric age. Large crystals of anorthite and augite, originally produced as crystal bombs of volcanic eruptions, are collected from a tuff breccia bed of the lowest part of Upper Miocene Mitaki Formation which unconformably covers the Nashino Formation.Large pseudomorph specimens of high-quartz are obtained from matrix-supported conglomerate, tufffaceous sandstone or pebble-containing mudstone beds, which strata overlie the Mitaki Formation. Zircon grains from the high-quartz horizon are dated to 8.0±0.7 Ma as fission-track age by the LA-ICP-MS method combined with the U-Pb dating. The strata including high-quartz horizon beds, often showing chaotic or dipping, are covered by a flat bed of clast-supported conglomerate underlying the Pliocene Tatsunokuchi Formation. They belong not to the Pliocene Kameoka Formation as a conventional thought, but probably to the Upper MioceneShirasawa Formation or the upper part of Nashino Formation, which two formations have been regarded as contemporaneous to the Mitaki Formation. Possibly, high-quartz have been derived from pumice tuff of the Nashino Formation which had been exposed in adjacent area at that time

Slope failures over a wide area in the 2018 Hokkaido Eastern Iburi Earthquake and its evaluation

The 2018 Hokkaido Eastern Iburi Earthquake caused a large amount of slope failures over a wide area.In particular, the enormous damage due to slope failures was centered in Atsuma and Abira town which are to the north of the epicenter. In Atsuma town, a seismic intensity of seven has been observed for the first time in Hokkaido, Japan. The geology in this region was mainly formed from three kinds of pyroclastic fall deposits (fa) erupted from Tarumae volcano, Eniwa volcano, and Shikotsu Caldera.Especially, the serious damage was generated in these tephra stratus. This report summarizes earthquake-induced damages on natural slopes, and presents physical feature and mechanical properties of the collapsed pyroclastic fall deposits distributed over this area.特