タカハシ　リョウヤ   Takahashi Ryoya   高橋　良哉    所属   東邦大学  薬学部 薬学科    職種   教授
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Age-related change of endocytic receptors megalin and cubilin in the kidney in rats
掲載誌名	正式名：Biogerontology 略　 称：Biogerontology ISSNコード：13895729
巻・号・頁	8(5),pp.505-515
著者・共著者	Odera K†, Goto S, Takahashi R†＊
担当区分	最終著者,責任著者
発行年月	2007/10
概要	Megalin and cubilin are the major endocytic receptors responsible for resorption of glomerular filtrate proteins, particularly albumin, in the renal proximal tubule. In order to better understand the mechanism of the development of albuminuria with age in rats, we investigated age-related change of the amount and cellular localization of both receptors in the kidney. Immunoblot analysis of the kidney extracts showed that the amount of megalin significantly decreased with age. Although there was no age-related change in the amount of intact cubilin, the amount of cubilin fragments increased with age. Immunohistochemical study revealed that megalin and cubilin were predominantly localized in brush border membrane of proximal tubular cells in young rats, but the receptors tended to diffuse into the cytoplasm in the old rats. Interestingly, low but significant amounts of megalin and cubilin were present in the glomerular cells in addition to the proximal tubular cells. The quantity of receptors progressively increased in the glomerulus with age. This age-related increase might be to compensate for the age-related defect of the uptake of albumin by the proximal tubules. Thus, although it is unclear whether megalin and cubilin in the glomerulus contribute to the uptake of albumin in primary urine, the age-related increase in the amount of albumin in urine might at least partly be due to quantitative and qualitative alterations of both receptors in the proximal tubule.