@article{oai:kyukan.repo.nii.ac.jp:00000183, author = {船越, 崇行 and 井上, 武 and 島田, 秀昭 and 児島, 昭次}, issue = {1}, journal = {九州看護福祉大学紀要, The Journal of Kyushu University of Nursing and Social Welfare}, month = {Mar}, note = {110000035464, The present study was designed to clarify the mechanism of nickel uptake in primary cultures of rat hepatocytes. Exposure of the hepatocytes to Ni (2~50 μM;as NiCl2) for up to 6h was not cytotoxic, as assessed by the tetrazolium-based dye (MTT) assay. Hepatocytes were treated with 10μM NiCl2 in the absence or presence of calcium (Ca) and magnesium (Mg) (1mM). Ni uptake was increased by 19% in medium lacking Mg or Ca and was increased by 37℃ in Ca and Mg-Free medium. The role of Ca channels on Ni uptake by the hepatocytes was investigated. Pretreatement with nicardipine of verapamil (200μM), potent inhibitor of Ca channels, decreased Ni uptake by 20%. This effect was only observed when the cells were incubated in the absence of Ca. Pretreatment with vasopressin (100μM), a well known Ca channel agonist, significantly increased Ni uptake by the hepatocytes (24%). To determine the involvement of carrier-mediated processes on Ni uptake, the effect of temperature was also investigated. At 4℃ the Ni uptake was decreased by 20% compared to uptake at 37℃. These results indicate that Ni uptake by the hepatocytes occurs, at least in part, through the Ca channel transport processes. Further study will be required to assess what other mechanisms are involved., ニッケル(Ni)は生体内微量元素で、RNAの安定化や特定の酵素活性(Arginase, Amino acid decarboxylase, Phosphoglucomutase, Acetyl CoA synsetase 等々)の発現に必須である。欠乏症としては、生殖低下、肝脂質・リン脂質代謝異常、グリコーゲン代謝低下等がある。一方、Niは環境汚染物質の一つであり、鋼材、合金材料、電子機器、メッキ、触媒、電池、台所器具等に使用され、日常的に暴露されている。その経口毒性は比較的低く、Cu,Co,Zn等必須金属と同程度であるが、化合物として気道・肺から吸入されると肺炎・肺うっ血・浮腫、肝・腎炎等の毒性が大きい。本研究では、ラット初代培養肝細胞を用いてNiの肝細胞内への取り込み機構について検討した。その結果、2~50μM Ni存在下で37℃、6時間培養しても細胞毒性は認められず、Ca,Mg非存在下ではNiの細胞内取り込み量が19%上昇した。また、Caチャネルの強力な阻害剤ニカルジピン及びベラパミルで前処理すると取り込み量は20%減少し、作動薬のバソプレシンで前処理すると24%上昇した。このことからNiの肝細胞内取り込みにCaチャネルの一部関与が推察された。}, pages = {83--91}, title = {ラット初代培養肝細胞におけるニッケルの取り込み機構:カルシウムチャネルの役割}, volume = {5}, year = {2003} }