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Membrane depolarization combined with release of calcium from internal stores does not trigger secretion from PC 12 cells.
- Source :
-
Receptors & channels [Recept Channels] 1993; Vol. 1 (3), pp. 217-20. - Publication Year :
- 1993
-
Abstract
- The mechanisms underlying catecholamine release from pheochromocytoma (PC 12) cells were examined. Whereas application of 1 microM bradykinin (BK) induced an increase in intracellular calcium ([Ca2+])i), either in medium containing 1.8 mM Ca2+ or in medium prepared without the addition of CaCl2 ("Ca(2+)-free medium"), norepinephrine ([3H]NE) release was induced only in Ca(2+)-containing medium. Similarly depolarization by 50 mM potassium induced [3H]NE release only in 1.8 mM calcium-containing medium. The combination of membrane depolarization (50 mM KCl) with increased [Ca2+]i secondary to BK application in "Ca(2+)-free medium" did not induce catecholamine secretion. It was concluded that Ca2+ entry through calcium channels at the plasma membrane is essential for the activation of catecholamine release. A rise in [Ca2+]i (4-5 times x basal) released from internal stores is not sufficient to trigger secretion from PC 12 cells, either by itself or in combination with membrane depolarization.
Details
- Language :
- English
- ISSN :
- 1060-6823
- Volume :
- 1
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Receptors & channels
- Publication Type :
- Academic Journal
- Accession number :
- 7922021