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Ca(2+) influx stimulated phospholipase C activity in bovine adrenal chromaffin cells: responses to K(+) depolarization and histamine
- Source :
- European journal of pharmacology. 398(2)
- Publication Year :
- 2000
-
Abstract
- The role of Ca(2+) influx in activating phospholipase C in bovine adrenal chromaffin cells has been investigated. Phospholipase C activity in response to K(+) depolarization (56 mM) was blocked by the L-type Ca(2+) channel antagonist nifedipine and partially inhibited by the omega-conotoxins GVIA and MVIIC. In contrast, phospholipase C activity in response to histamine receptor activation was unaffected by omega-conotoxin GVIA and partially inhibited by omega-conotoxin MVIIC or nifedipine. This response was however markedly inhibited by the non-selective Ca(2+) channel antagonists La(3+) or 1-[beta-[3-(4-Methoxyphenyl)propoxy]-4-methoyphenethyl]-H-imidazol e (SKF-96365). Despite this Ca(2+) dependence phospholipase C activity was not increased during periods of "capacitative" Ca(2+) inflow generated by histamine-, caffeine- or thapsigargin-mediated depletion of internal Ca(2+) stores. Thus, while Ca(2+) influx in response to K(+) depolarization or G-protein receptor activation can increase phospholipase C activity in these cells, in the latter case it appears to be ineffective unless there is concurrent agonist occupation of the receptor.
- Subjects :
- medicine.medical_specialty
Nifedipine
Chromaffin Cells
Inositol Phosphates
complex mixtures
omega-Conotoxins
Histamine receptor
chemistry.chemical_compound
omega-Conotoxin GVIA
Internal medicine
Adrenal Glands
medicine
Animals
Omega-Conotoxin GVIA
Calcium Signaling
Cells, Cultured
Pharmacology
Phospholipase C
Voltage-dependent calcium channel
Chemistry
Imidazoles
Depolarization
Calcium Channel Blockers
medicine.anatomical_structure
Endocrinology
Type C Phospholipases
Chromaffin cell
Potassium
Calcium
Cattle
Calcium Channels
Adrenal medulla
Histamine
Subjects
Details
- ISSN :
- 00142999
- Volume :
- 398
- Issue :
- 2
- Database :
- OpenAIRE
- Journal :
- European journal of pharmacology
- Accession number :
- edsair.doi.dedup.....ae82eeb4563f93ce993436b38c9a1dbe