Somatostatin, misoprostol and galanin inhibit gastrin- and PACAP-stimulated secretion of histamine and pancreastatin from ECL cells by blocking specific Ca(2+) channels.
(2005) In Regulatory Peptides 130(1-2). p.81-90- Abstract
- The oxyntic mucosa is rich in ECL cells. They secrete histamine and chromogranin A-derived peptides, such as pancreastatin, in response to gastrin and pituitary adenylate cyclase-activating peptide (PACAP). Secretion is initiated by Ca2+ entry. While gastrin stimulates secretion by opening L-type and N-type Ca2+ channels, PACAP stimulates secretion by activating L-type and receptor-operated Ca2+ channels. Somatostatin, galanin and prostaglandin E2 (PGE2) inhibit gastrin- and PACAP-stimulated secretion from the ECL cells. In the present study, somatostatin and the PGE2 congener misoprostol inhibited gastrin- and PACAP-stimulated secretion 100%, while galanin inhibited at most 60–65%. Bay K 8644, a specific activator of L-type Ca2+ channels,... (More)
- The oxyntic mucosa is rich in ECL cells. They secrete histamine and chromogranin A-derived peptides, such as pancreastatin, in response to gastrin and pituitary adenylate cyclase-activating peptide (PACAP). Secretion is initiated by Ca2+ entry. While gastrin stimulates secretion by opening L-type and N-type Ca2+ channels, PACAP stimulates secretion by activating L-type and receptor-operated Ca2+ channels. Somatostatin, galanin and prostaglandin E2 (PGE2) inhibit gastrin- and PACAP-stimulated secretion from the ECL cells. In the present study, somatostatin and the PGE2 congener misoprostol inhibited gastrin- and PACAP-stimulated secretion 100%, while galanin inhibited at most 60–65%. Bay K 8644, a specific activator of L-type Ca2+ channels, stimulated ECL-cell secretion, an effect that was inhibited equally effectively by somatostatin, misoprostol and galanin (75–80% inhibition). Pretreatment with pertussis toxin, that inactivates inhibitory G-proteins, prevented all three agents from inhibiting stimulated secretion (regardless of the stimulus). Pretreatment with nifedipine (10 μM), an L-type Ca2+ channel blocker, reduced PACAP-evoked pancreastatin secretion by 50–60%, gastrin-evoked secretion by not, vert, similar 80% and abolished the response to Bay K 8644. The nifedipine-resistant response to PACAP was abolished by somatostatin and misoprostol but not by galanin. Gastrin and PACAP raised the intracellular Ca2+ concentration in a biphasic manner, believed to reflect mobilization of internal Ca2+ followed by Ca2+ entry. Somatostatin and misoprostol blocked Ca2+ entry (and histamine and pancreastatin secretion) but not mobilization of internal Ca2+.
The present observations on isolated ECL cells suggest that Ca2+ entry rather than mobilization of internal Ca2+ triggers exocytosis, that gastrin and PACAP activate different (but over-lapping) Ca2+ channels, that somatostatin, misoprostol and galanin interact with inhibitory G-proteins to block Ca2+ entry via L-type Ca2+ channels, and that somatostatin and misoprostol (but not galanin) in addition block N-type and/or receptor-operated Ca2+ channels. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/140255
- author
- Björkqvist, Maria LU ; Lundgren, Maria LU ; Eliasson, Lena LU ; Håkanson, Rolf LU and Lindström, Erik
- organization
- publishing date
- 2005
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Gastrin, PACAP, Bay K 8644, PRL-2903, Galanin, Somatostatin, PGE2, Misoprostol
- in
- Regulatory Peptides
- volume
- 130
- issue
- 1-2
- pages
- 81 - 90
- publisher
- Elsevier
- external identifiers
-
- wos:000230973700012
- pmid:15935492
- scopus:22044443032
- pmid:15935492
- ISSN
- 1873-1686
- DOI
- 10.1016/j.regpep.2005.04.002
- language
- English
- LU publication?
- yes
- id
- 13b9175d-c4d9-403d-9de9-ac4cde1b4835 (old id 140255)
- alternative location
- http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15935492
- date added to LUP
- 2016-04-01 12:31:41
- date last changed
- 2023-09-02 10:51:53
@article{13b9175d-c4d9-403d-9de9-ac4cde1b4835, abstract = {{The oxyntic mucosa is rich in ECL cells. They secrete histamine and chromogranin A-derived peptides, such as pancreastatin, in response to gastrin and pituitary adenylate cyclase-activating peptide (PACAP). Secretion is initiated by Ca2+ entry. While gastrin stimulates secretion by opening L-type and N-type Ca2+ channels, PACAP stimulates secretion by activating L-type and receptor-operated Ca2+ channels. Somatostatin, galanin and prostaglandin E2 (PGE2) inhibit gastrin- and PACAP-stimulated secretion from the ECL cells. In the present study, somatostatin and the PGE2 congener misoprostol inhibited gastrin- and PACAP-stimulated secretion 100%, while galanin inhibited at most 60–65%. Bay K 8644, a specific activator of L-type Ca2+ channels, stimulated ECL-cell secretion, an effect that was inhibited equally effectively by somatostatin, misoprostol and galanin (75–80% inhibition). Pretreatment with pertussis toxin, that inactivates inhibitory G-proteins, prevented all three agents from inhibiting stimulated secretion (regardless of the stimulus). Pretreatment with nifedipine (10 μM), an L-type Ca2+ channel blocker, reduced PACAP-evoked pancreastatin secretion by 50–60%, gastrin-evoked secretion by not, vert, similar 80% and abolished the response to Bay K 8644. The nifedipine-resistant response to PACAP was abolished by somatostatin and misoprostol but not by galanin. Gastrin and PACAP raised the intracellular Ca2+ concentration in a biphasic manner, believed to reflect mobilization of internal Ca2+ followed by Ca2+ entry. Somatostatin and misoprostol blocked Ca2+ entry (and histamine and pancreastatin secretion) but not mobilization of internal Ca2+.<br/><br> <br/><br> The present observations on isolated ECL cells suggest that Ca2+ entry rather than mobilization of internal Ca2+ triggers exocytosis, that gastrin and PACAP activate different (but over-lapping) Ca2+ channels, that somatostatin, misoprostol and galanin interact with inhibitory G-proteins to block Ca2+ entry via L-type Ca2+ channels, and that somatostatin and misoprostol (but not galanin) in addition block N-type and/or receptor-operated Ca2+ channels.}}, author = {{Björkqvist, Maria and Lundgren, Maria and Eliasson, Lena and Håkanson, Rolf and Lindström, Erik}}, issn = {{1873-1686}}, keywords = {{Gastrin; PACAP; Bay K 8644; PRL-2903; Galanin; Somatostatin; PGE2; Misoprostol}}, language = {{eng}}, number = {{1-2}}, pages = {{81--90}}, publisher = {{Elsevier}}, series = {{Regulatory Peptides}}, title = {{Somatostatin, misoprostol and galanin inhibit gastrin- and PACAP-stimulated secretion of histamine and pancreastatin from ECL cells by blocking specific Ca(2+) channels.}}, url = {{http://dx.doi.org/10.1016/j.regpep.2005.04.002}}, doi = {{10.1016/j.regpep.2005.04.002}}, volume = {{130}}, year = {{2005}}, }