ラット膵島B細胞の刺激-放出連関の温度依存性に関する研究 Temperature effects on stimulus-secretion coupling in rat pancreatic B cells

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著者

    • 丹羽, 光一 ニワ, コウイチ

書誌事項

タイトル

ラット膵島B細胞の刺激-放出連関の温度依存性に関する研究

タイトル別名

Temperature effects on stimulus-secretion coupling in rat pancreatic B cells

著者名

丹羽, 光一

著者別名

ニワ, コウイチ

学位授与大学

北海道大学

取得学位

博士 (獣医学)

学位授与番号

甲第3909号

学位授与年月日

1996-03-25

注記・抄録

博士論文

The present study was designed to examine 1) the correlation between the secretory response of insulin and the dynamics of cytoplasmic calcium concentration([Ca2+]i) induced by glucose and 2) the effects of lowering temperature on the processes proximal and distal to Ca2+ signaling in pancreatic B cells. Glucose (15mM) caused a biphasic increase in insulin secretion in perifused pancreatic islets o f rat at 35℃: that is, the secretory response consisted of a transient increase followed by a nadir (first phase) and gradual increase (second phase). Glucose caused a biphasic increase in [Ca2+]i in fura-2-loaded islets at 35℃, a transient increase(first phase) followed by a gradual increase (second phase) on which recurrent Ca2+ spikes were frequently superimposed. Time courses of the first and the second phases of the [Ca2+]i increase corresponded to those of the insulin secretion, suggesting that the biphasic insulin secretion is underlain by the biphasic [Ca2+]i increase. The insulin secretion and the [Ca2+]i inerease were decreased by lowering temperature to 30 or 25℃ with a temperature coefficient (Q10) of 11.6 and 1.8, respectively. The ratio of glucose-induoed insulin secretion to the [Ca2-]i increase (IS/Ca) was calculated to represent the efficiency o f Ca2+ to cause exocytosis. The Q10 value of the ratio of IS/Ca was calculated to be 3.7 timcs grcater(6.6) than that of the [Ca2+]i increase, suggcsting that the exocytotic process is more sensitive to temperature than the [Ca2+]i increase. The effects of lowering temperature on the insulin secretion and the [Ca2+]i increase induced by high K+(30mM), carbamylcholine (CCh; 100mM), and glibenclamide (2mM) were also examined. The Q10 values of the ratios of IS/Ca in the responses to high K+, CCh, and glibenclamide were 5.6, 3.8, and 13.0, respectively. These values were greater than the Q10 values of corresponding [Ca2+]i responses (1.2, 1.4, and 1.8, respectively), suggesting that the inhibition of insulin secretion could be attributed to temperature sensitivity of the exocytotic process regardless of the cause of [Ca2+]i increase. It is concluded that: 1) the glucose-induced biphasic insulin secretion is underlain by the biphasic [Ca2+]i increase;2) lowering tempcrature inhibits both processes proximal and distal to Ca2+ signaling in response to glucose; and 3) the latter process is more sensitive to temperature than the former in rat pancreatic B cells.

46p.

Hokkaido University(北海道大学). 博士(獣医学)

目次

  1. 目次 / (0003.jp2)
  2. 緒論 / p1 (0005.jp2)
  3. 材料と方法 / p5 (0009.jp2)
  4. 1.実験動物 / p5 (0009.jp2)
  5. 2.灌流液の組成 / p5 (0009.jp2)
  6. 3.摘出膵血管灌流標本の作製 / p5 (0009.jp2)
  7. 4.摘出膵血管灌流標本の灌流方法とサンプルの採取方法 / p6 (0010.jp2)
  8. 5.膵島の単離と初代培養 / p7 (0011.jp2)
  9. 6.単離膵島標本の[Ca²⁺]i測定法 / p8 (0012.jp2)
  10. 7.単離膵島標本の表面灌流方法 / p9 (0013.jp2)
  11. 8.灌流温度の調節 / p9 (0013.jp2)
  12. 9.インスリン測定法 / p10 (0014.jp2)
  13. 10.温度係数の計算 / p11 (0015.jp2)
  14. 11.試薬 / p11 (0015.jp2)
  15. 結果 / p12 (0016.jp2)
  16. 1.ぶどう糖刺激によるインスリン分泌反応と[Ca²⁺]i変化 / p12 (0016.jp2)
  17. 2.ぶどう糖刺激による膵島のインスリン分泌反応の温度依存性 / p14 (0018.jp2)
  18. 3.ぶどう糖刺激による膵島の[Ca²⁺]i変化の温度依存性 / p14 (0018.jp2)
  19. 4.ぶどう糖刺激時のインスリン分泌と[Ca²⁺]iの比率(IS/Ca比)の温度依存性 / p16 (0020.jp2)
  20. 5.ぶどう糖刺激時のインスリン分泌、[Ca²⁺]i、及びIS/Ca比の温度係数 / p20 (0024.jp2)
  21. 6.高濃度K⁺、カルバミルコリン(CCh)、及びグリベンクラミドによるインスリン分泌反応の温度依存性 / p20 (0024.jp2)
  22. 7.高濃度K⁺、CCh、及びグリベンクラミドによる[Ca²⁺]i変化の温度依存性 / p22 (0026.jp2)
  23. 8.高濃度K⁺、CCh、及びグリベンクラミドによる刺激時のインスリン分泌、[Ca²⁺]i、及びIS/Ca比の温度係数 / p23 (0027.jp2)
  24. 考察 / p27 (0031.jp2)
  25. 1.インスリン分泌と膵島[Ca²⁺]iの相関 / p27 (0031.jp2)
  26. 1.1.2相性インスリン分泌反応と眸島[Ca²⁺]iの時間的対応 / p27 (0031.jp2)
  27. 1.2.ぶどう糖刺激によるインスリン分泌反応の第1相と第2相の相違 / p28 (0032.jp2)
  28. 2.温度の影響 / p29 (0033.jp2)
  29. 2.1.ぶどう糖刺激によるB細胞の刺激-放出連関の温度依存性 / p29 (0033.jp2)
  30. 2.2.膵島と単離B細胞の[Ca²⁺]i変化の温度依存性 / p30 (0034.jp2)
  31. 2.3.高濃度K⁺、CCh、及びグリベンクラミドによる刺激-放出連関の温度依存性 / p32 (0036.jp2)
  32. 2.4.B細胞の刺激-放出連関の特異性 / p33 (0037.jp2)
  33. 要約 / p34 (0038.jp2)
  34. 謝辞 / p37 (0041.jp2)
  35. 引用文献 / p38 (0042.jp2)
  36. 英文要旨 / p46 (0050.jp2)
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各種コード

  • NII論文ID(NAID)
    500000132911
  • NII著者ID(NRID)
    • 8000000967496
  • DOI(NDL)
  • 本文言語コード
    • jpn
  • NDL書誌ID
    • 000000297225
  • データ提供元
    • 機関リポジトリ
    • NDL-OPAC
    • NDLデジタルコレクション
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