肥満, 高脂血ラット (Zucker Fatty Rat) におけるインスリン作用の特異性に関する研究 [I]:"脂肪細胞Insulin Receptorの結合能力並びにProinsulin存在下のInsulin親和性について"

スポンサーリンク

概要

• 論文の詳細を見る

• The interaction of insulin and insulin receptor was studied with epididymal fat cell membrane of Zucker fatty rats and compared with their thin littermates or wild type normal rats. Epididymal fat pads were removed from Zucker fatty rats (10-11 months old, body weight 600-700 g) and from thin littermates or normal rats (9-12 months old, body weight about 300 g). Purified plasma membranes were obtained by the Rodbell's method. <BR>Prepared cell membranes (130 μg protein) were incubated with <SUP>125</SUP>I-insulin (about 40 μU, specific activity 97 μCi/μg) and native insulin (0-20 μg) or native proinsulin (0-10 μg) in 0.1% bovine serum albumin Krebs-Ringer bicarbonate buffer (pH=7.4). Final incubation volume was 0.6 ml per tube. Incubation was performed for 20 minutes at 24°C. Labelled and native insulin bound to fat cell membrane were separated from free insulin by filtration through a millipore filter. Filters were washed with 5 ml of chilled Krebs-Ringer-bicarbonate buffer and the specifically bound radioactivity was counted. <BR>The following results were obtained : <BR>1) The insulin binding capacity per mg protein of epididymal fat cell membranes from Zucker fatty rats was about 40% of that from control rats. <BR>2) There were two or more receptor sites on fat cell membranes from both Zucker fatty rats and control rats. The equilibrium constant (Km) of high affinity site was about 2.9-4.4 × 10<SUP>-9</SUP> mol/1. <BR>3) In Zucker fatty rats, inhibiting effect of unlabelled proinsulin on the binding of <SUP>125</SUP> I-insulin to fat cell membrane was slightly more potent than in the control rats. <BR>4) The specific insulin binding capacity on cell membrane was readily altered by medium glucose concentration in all strains of rats.

• 一般社団法人 日本内分泌学会の論文

著者

• 上田 賀美

  和歌山県立医科大学内科内分泌部門

関連論文

• 肥満, 高脂血ラット (Zucker Fatty Rat) におけるインスリン作用の特異性に関する研究 [II]:"脂肪細胞におけるインスリン特異結合能と結合インスリンの生物効果"
• 肥満, 高脂血ラット (Zucker Fatty Rat) におけるインスリン作用の特異性に関する研究 [I]:"脂肪細胞Insulin Receptorの結合能力並びにProinsulin存在下のInsulin親和性について"

スポンサーリンク