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Somatostatin, misop...
Somatostatin, misoprostol and galanin inhibit gastrin- and PACAP-stimulated secretion of histamine and pancreastatin from ECL cells by blocking specific Ca(2+) channels.
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- Björkqvist, Maria (author)
- Lund University,Lunds universitet,Institutionen för experimentell medicinsk vetenskap,Medicinska fakulteten,Biomarkörer vid hjärnsjukdomar,Forskargrupper vid Lunds universitet,Translationell neuroendokrinologi,Department of Experimental Medical Science,Faculty of Medicine,Biomarkers in Brain Disease,Lund University Research Groups,Translational Neuroendocrinology
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- Lundgren, Maria (author)
- Lund University,Lunds universitet,Avdelningen för mikrobiologi, immunologi och glykobiologi - MIG,Institutionen för laboratoriemedicin,Medicinska fakulteten,Division of Microbiology, Immunology and Glycobiology - MIG,Department of Laboratory Medicine,Faculty of Medicine
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- Eliasson, Lena (author)
- Lund University,Lunds universitet,Diabetes - öcellsexocytos,Forskargrupper vid Lunds universitet,Diabetes - Islet Cell Exocytosis,Lund University Research Groups
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- Håkanson, Rolf (author)
- Lund University,Lunds universitet,Drug Target Discovery,Forskargrupper vid Lunds universitet,Lund University Research Groups
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Lindström, Erik (author)
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(creator_code:org_t)
- Elsevier BV, 2005
- 2005
- English.
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In: Regulatory Peptides. - : Elsevier BV. - 1873-1686 .- 0167-0115. ; 130:1-2, s. 81-90
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http://www.ncbi.nlm....
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http://dx.doi.org/10...
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Abstract
Subject headings
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- 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.
Subject headings
- MEDICIN OCH HÄLSOVETENSKAP -- Medicinska och farmaceutiska grundvetenskaper -- Cell- och molekylärbiologi (hsv//swe)
- MEDICAL AND HEALTH SCIENCES -- Basic Medicine -- Cell and Molecular Biology (hsv//eng)
Keyword
- Gastrin
- PACAP
- Bay K 8644
- PRL-2903
- Galanin
- Somatostatin
- PGE2
- Misoprostol
Publication and Content Type
- art (subject category)
- ref (subject category)
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