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1999 Fiscal Year Final Research Report Summary

Molecular mechanisms of salivary exocytosis-endocytosis coupling

Research Project

Project/Area Number 09671866
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Morphological basic dentistry
Research InstitutionKitasato University

Principal Investigator

SEGAWA Akihisa  Kitasato Univ. School of Medicine, Assistant Professor, 医学部, 講師 (50154638)

Project Period (FY) 1997 – 1999
KeywordsSalivary glands / exocytosis / endocytosis / calcium / IPィイD23ィエD2 receptor
Research Abstract

This research project is aimed to clarify the molecular mechanisms involved in exocytosis-endocytosis coupling in salivary glands by morphological/functional/biochemical approaches. This year, analyses were performed on whole gland perfusion system, calcium signaling and parotid glands in l3-galactosidase knock-out mice.
1) Whole gland perfusion: Isolated whole parotid glands of rats were perfused arterially with isoproterenol (β-agonist) or carbachol (muscarinic agonist), and secreted saliva and tissues were collected sequentially; β-stimulation evoked exocytosis following which the fused granule membranes were removed one by one. Muscarinic stimulation inhibited this removal process. Since muscarinic stimulation causes fluid secretion but β-stimulation does not, it is suggested that membrane retrieval process plays significant roles in regulation of fluid secretion.
2) Calcium signaling: High speed cofocal microscopy of living parotid glands showed the synchronized response in acini and the non-synchronized response in ducts. Gap junction was detected between acinar cells but not duct cells. Acini are likely to function as a syncitium.
3) β-galactosidase knock-out mice: β-galactosidase is involved in the lysosomal degradation of membrane components. Parotid acinar cells in mice deficient in this enzyme revealed vacuolar profiles in the cytoplasm. Electron microscopic observation demonstrated that the vacuoles appeared in the RER region. Unexpectedly, this enzyme is suggested to play roles in the biosynthetic processes rather than the degradation.

  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] A. Segawa: "Measurement of secretion in confocal microscopy"Methods in Endymology. 307. 328-340 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] N. Nowroozi, S Kim, A Segawa et al: "Hih Lenals of GM_1Gangliosidase in the panotid gland"Otoloryngologic Clinics of North America. 32. 779-791 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M. Takamura, S. Yamashita, A. Segawa: "Hillisecord analyses of Ca^<2+> initiation sites evolsed muscarinic stimulation in exocine alimar cells"Biochem Biophys. Res. Comm.. 259. 656-660 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] K. Yoshimura, M. Murakami, A. Segawa: "Carbachol induced Ca increase, but not activation of protein kinase c, stimulates exocytsis in rat parotid acim"J. Physiol.(London). 522. 403-416 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] A. Segawa, F. Loffredo et al: "Cell Biology of human salivary secretion"European Journal of Morphology. (in press). (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M. Murakami, K. Yoshimura, A. Segawa et al: "Relationship between anuylase and fluid secretion in the isolated parfiosel abobe pawtid gland of the rat"European Journal of Morpholoy. (in press). (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] A Segawa: "Measurement of secretion in confocal microscopy."Methods in Enzymology. Vol 307"Confocal Microscopy" (PM Conn ed) Academic Press. 328-340 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] H Takemura, S Yamashina, A Segawa: "Millisecond analysis of Ca2+ initiation sites evoked by muscarinic receptor stimulation in exocrine acinar cells"Biochemical Biophysical Research Communications. 259. 656-660 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] N Nowroozi, S Kim, A Segawa, H Warita, D Rice, PC Denny, JH Zernik: "High levels of GM1 ganglioside and the GM1-galactosidase in the partoid gland - a new model for secretory mechanisms of the partoid gland"Otolaryngologic Clinics of North America. 32. 779-791 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] K Yoshimura, M Murakami, A Segawa: "Carbachol induced Ca increase, but not activation of protein kinase C, stimulates exocytosis in rat parotid acini"Joumal of physiology (London). 522. 403-416 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A Segawa, F Loffredo, R Puxeddu, S Yamashina, F Testa Riva, A Riva: "Cell biology of human saliva secretion"European Journal of Morphology. (in press).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M Murakami, K Yoshimura, A Segawa, F Loffredo, A Riva: "Relationship between amylase and fluid secretion in the isolated perfused whole parotid of the rat"European Journal of Morphology. (in press).

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2001-10-23  

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