Journal of Neuroscience, Vol 6, 1719-1725, Copyright © 1986 by Society for Neuroscience
Cooperative regulation of neurotensin content in PC12 pheochromocytoma cell cultures: effects of nerve growth factor, dexamethasone, and activators of adenylate cyclase
AS Tischler, YC Lee, D Costopoulos, VW Slayton, WJ Jason and SR Bloom
Nerve growth factor, dexamethasone, and forskolin or cholera toxin (CT) act
cooperatively to increase the content of neurotensin (NT) in PC12
pheochromocytoma cells. Relatively small increases in NT content occur in
the presence of NGF alone or dexamethasone alone, but not of forskolin or
CT alone. Increases of 10- to 100-fold occur in the presence of NGF plus
dexamethasone or NGF plus forskolin, and up to 600- fold increases occur in
the presence of all three agents. These increases are extremely stable and
persist for at least 2 weeks after removal of dexamethasone or forskolin.
The complex regulation of NT stores in PC12 cells might reflect mechanisms
that regulate NT content of normal chromaffin cells and/or neurons during
development or in adult life. A small amount of stored NT is released in
response to stimulation with 52 mM K+. This release is blocked in the
presence of 2 mM Co2+, suggesting that it occurs via Ca2+-mediated
exocytosis.