The exocytotic and crinophagic pathways in ECL cells of the rat stomach

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

Standard

The exocytotic and crinophagic pathways in ECL cells of the rat stomach. / Zhao, Chun-Mei.

Chun-Mei Zhao, Sölvegatan 10, 223 62 Lund, Sweden, 1999. 154 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

Harvard

Zhao, C-M 1999, 'The exocytotic and crinophagic pathways in ECL cells of the rat stomach', Doktor, Institutionen för experimentell medicinsk vetenskap.

APA

Zhao, C-M. (1999). The exocytotic and crinophagic pathways in ECL cells of the rat stomach. Chun-Mei Zhao, Sölvegatan 10, 223 62 Lund, Sweden,.

CBE

Zhao C-M. 1999. The exocytotic and crinophagic pathways in ECL cells of the rat stomach. Chun-Mei Zhao, Sölvegatan 10, 223 62 Lund, Sweden,. 154 s.

MLA

Zhao, Chun-Mei The exocytotic and crinophagic pathways in ECL cells of the rat stomach Chun-Mei Zhao, Sölvegatan 10, 223 62 Lund, Sweden,. 1999.

Vancouver

Zhao C-M. The exocytotic and crinophagic pathways in ECL cells of the rat stomach. Chun-Mei Zhao, Sölvegatan 10, 223 62 Lund, Sweden, 1999. 154 s.

Author

Zhao, Chun-Mei. / The exocytotic and crinophagic pathways in ECL cells of the rat stomach. Chun-Mei Zhao, Sölvegatan 10, 223 62 Lund, Sweden, 1999. 154 s.

RIS

TY - THES

T1 - The exocytotic and crinophagic pathways in ECL cells of the rat stomach

AU - Zhao, Chun-Mei

N1 - Defence details Date: 1999-05-10 Time: 10:15 Place: Sölvegatan 10 External reviewer(s) Name: Solcia, Enrico Title: Prof. Affiliation: University of Pavia, Italy ---

PY - 1999

Y1 - 1999

N2 - The ECL cells in the stomach produce, store and secrete a variety of secretory products, such as histamine and chromogranin A-derived peptides (e.g. pancreastatin). The functional significance of the ECL cells can be expected to reflect the nature/bioactivity of the secreted products. Although the anticipated peptide hormone of the ECL cells remains unidentified, ECL-cell histamine is recognized as an important paracrine messenger for gastric acid secretion. Based on the results of the present studies, we have classified the presumed secretory organelles of the ECL cells into the following categories: progranules, granules, secretory vesicles (immature and mature) and endocytotic microvesicles. The membrane of secretory organelles is furnished with vesicle monoamine transporter type 2, capable of accumulating histamine. The accumulation of histamine by progranules/granules appears to be associated with their transformation into large electron-lucent (but dense-cored) secretory vesicles. Mature secretory vesicles are to be found in the docking zone, i.e. close to the plasma membrane. When the ECL cell is stimulated (e.g. by gastrin), secretory vesicles in the docking zone undergo exocytosis. The process of exocytosis is coupled with endocytosis, resulting in an increased number of microvesicles in the docking zone. We suggest that progranules/granules and secretory vesicles form part of a secretory pathway which begins with Golgi-associated progranules/granules and ends with exocytosis of secretory vesicles. The actual process of exocytosis depends on a number of exocytotic proteins, many of which have been demonstrated in the ECL cells. The process of exocytosis is coupled with endocytosis and the formation of endocytotic microvesicles. When the ECL cells are excessively stimulated, secretory vesicles fuse not only with the plasma membrane but also with each other, forming large vacuoles. At the same time, lipofuscin bodies (age pigment) arise. We suggest that both vacuoles and lipofuscin bodies are manifestations of a crinophagic pathway, enabling the ECL cell to eliminate (or at least compartmentalize) superfluous secretory products

AB - The ECL cells in the stomach produce, store and secrete a variety of secretory products, such as histamine and chromogranin A-derived peptides (e.g. pancreastatin). The functional significance of the ECL cells can be expected to reflect the nature/bioactivity of the secreted products. Although the anticipated peptide hormone of the ECL cells remains unidentified, ECL-cell histamine is recognized as an important paracrine messenger for gastric acid secretion. Based on the results of the present studies, we have classified the presumed secretory organelles of the ECL cells into the following categories: progranules, granules, secretory vesicles (immature and mature) and endocytotic microvesicles. The membrane of secretory organelles is furnished with vesicle monoamine transporter type 2, capable of accumulating histamine. The accumulation of histamine by progranules/granules appears to be associated with their transformation into large electron-lucent (but dense-cored) secretory vesicles. Mature secretory vesicles are to be found in the docking zone, i.e. close to the plasma membrane. When the ECL cell is stimulated (e.g. by gastrin), secretory vesicles in the docking zone undergo exocytosis. The process of exocytosis is coupled with endocytosis, resulting in an increased number of microvesicles in the docking zone. We suggest that progranules/granules and secretory vesicles form part of a secretory pathway which begins with Golgi-associated progranules/granules and ends with exocytosis of secretory vesicles. The actual process of exocytosis depends on a number of exocytotic proteins, many of which have been demonstrated in the ECL cells. The process of exocytosis is coupled with endocytosis and the formation of endocytotic microvesicles. When the ECL cells are excessively stimulated, secretory vesicles fuse not only with the plasma membrane but also with each other, forming large vacuoles. At the same time, lipofuscin bodies (age pigment) arise. We suggest that both vacuoles and lipofuscin bodies are manifestations of a crinophagic pathway, enabling the ECL cell to eliminate (or at least compartmentalize) superfluous secretory products

KW - toxicology

KW - ECL cells - Exocytosis - Crinophagia - Histamine - Gastrin - Morphometry - Stomach - Ultrastrucuture

KW - pharmacognosy

KW - pharmacy

KW - Pharmacological sciences

KW - Farmakologi

KW - farmakognosi

KW - farmaci

KW - toxikologi

M3 - Doctoral Thesis (compilation)

SN - 91-628-3507-6

PB - Chun-Mei Zhao, Sölvegatan 10, 223 62 Lund, Sweden,

ER -