A study of exocrine cell functions using local photolysis of caged compounds.

• Project/Area Number: 06454144
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: General physiology
• Research Institution: The University of Tokyo
• Principal Investigator: KASAI Haruo Dept.physiol., Facult.Med., Univ.Tokyo, Associate Professor, 医学部・第一生理, 助教授 (60224375)
• Project Period (FY): 1994 – 1995
• Project Status: Completed (Fiscal Year 1995)
• Budget Amount: ¥6,900,000 (Direct Cost: ¥6,900,000); Fiscal Year 1995: ¥2,800,000 (Direct Cost: ¥2,800,000); Fiscal Year 1994: ¥4,100,000 (Direct Cost: ¥4,100,000)
• Keywords: Calcium / Exocrine gland / Exocytosis / Patch Clamp / Zymogeu granule / Acetylcholine / Caged compounds / カルシウム(Ca) / 外分泌腺 / イオンチャネル

Research Abstract

Agonists evoke Ca^<2+> gradients and oscillations initiating at the trigger zone in exocrine acinar cells. Using a low affinity Ca^<2+> indicator dye, BTC,we found that agonists raised Ca^<2+> concentration as high as 10 muM at the trigger zone. Comparison with the results obtained with fura-2 suggests profuse Ca^<2+> release and Ca^<2+> domains at the trigger zone. The resulting micromolar Ca^<2+> gradients were necessary and sufficient for exocytosis of zymogen granules investigated with the capacitance measurement. In contrast, submicromolar Ca^<2+> gradients selectively gave rise to sequential activation of luminal and basal ion channels. These results emphasize critical role of the micromolar Ca^<2+> gradients in exocytosis, and prompt reinvestigation of other cells using low affinity Ca^<2+> indicators.

Research Products

• [Publications] Terauchi Y. et al.: "Pancreaticβ-cell-specific fargeted disrnption of gluco kinase gene." J. Biol. Chem.270. 30253-30256 (1995)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Kasai H. et al.: "Two compovents of exocytosis and eudocytosis in PC12 cells sxdied using coged-Ca^<2+> compounds." J.Physiology. (印刷中).
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Ninomiya Y. et al.: "Ca^<2+> dependent exocytobc psthmays in CHO-fibroblast revealed by capacitauce unersuvement and caged-Ca^<2+> compound." J.Physiology. (印刷中).
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Ito, et al.: "Microucolar Ca^<2+> gradients regulating exocytotic secretion from exocrine paucveas." 投稿中.
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Kasai. et al.: "Paureats Ca^<2+> waves and secvetion" Celciu waves, gradients and osillation (Ciba Foundation Symposium 188)Wiley, Chichestes. 104-120 (1995)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Kasai, H.: "Pancreatic Ca^<2+> waves and secretion. In Calcium waves, gradients and oscillations." Wiley, Chichester (Ciba Foundation Symposium 188). 104-120 (1995)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Terauchi, Y., Sakura, H., Yasuda, K., Iwamoto, K., Takahashi, N., Ito, K., Kasai, H., Suzuki, H., Ueda., Kamada, N., Jishage, K., Komeda, K., Noda, M., Kanazawa, Y., Taniguchi, S., Miwa, I., Akanuma, Y., Kodama, T., Yazaki, Y.& Kadowaki, T.: "Pancreatic beta-cell-specific targeted disruption of glucokinase gene." J.Biol.Chem. 270. 30253-30256 (1995)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Kasai, H., Takagi, H., Ninomiya, Y., Kishimoto, T., Yosida, A., Yoshioka, T.& Miyashita, Y.: "Two components of exocytosis and endocytosis in PC12 cells studied using caged-Ca^<2+> compounds." J.Physiology. (in press). (1996)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Ninomiya, A., Kishimoto, T., Miyashita, Y.& Kasai, H.: "Ca^<2+> -dependent exocytotic pathways in CHO fibroblast revealed by capacitace measurement and caged-Ca^<2+> compound." J.Physiology. (in press). (1996)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Kasai,H.et al.: "Two components of exocytosis and endocytosis in PC12 cells stndied using caged Ca^<2+> compound." J.Physiology. in press.
• [Publications] Ninomiya,et al.: "Ca^<2±> deperdent exocytotic pathmcys in CHD fibroblats renealed by capaeitance measurement and a caged-Ca^<2+> compound" J.Physiology. in press.
• [Publications] Terauchi et al.: "Pancreatic β-cell-specific targcted disrmption of glneoheivose gene" J.Biological Chemistry. 270. 30253-30256 (1995)