Permissive effect of dexamethasone on the increase of proenkephalin mRNA induced by depolarization of chromaffin cells
In cultured bovine chromaffin cells, changes in the dynamic state of enkephalin stores elicited experimentally were studied by measuring cellular proenkephalin mRNA, as well as enkephalin precursors and authentic enkephalin content of cells and culture media. In parallel, tyrosine hydroxylase mRNA and catecholamine cell content were also determined. Low concentrations (0.5-100 pM) of dexamethasone increased the cell contents of proenkephalin mRNA and enkephalin-containing peptides. High concentrations of the hormone(1 ..mu..M) were required to increase the cell contents of tyrosine hydroxylase mRNA and catecholamines. Depolarization of the cells with 10 ..mu..M veratridine resulted in a depletion of enkephalin and catecholamine stores after 24 hr. The enkephalin, but not the catecholamine, content was restored by 48 hr. An increase in proenkephalin mRNA content might account for the recovery; this increase was curtailed by tetrodotoxin and enhanced by 10 pM dexamethasone. Tyrosine hydroxylase mRNA content was not significantly modified by depolarization, even in the presence of 1 ..mu..M dexamethasone. Aldosterone, progesterone, testosterone, or estradiol (1 ..mu..M) failed to change proenkephalin mRNA. Hence, dexamethasone appears to exert a specific permissive action on the stimulation of the proenkephalin gene elicited by depolarization. Though the catecholamines and enkephalins are localized in the same chromaffin granules and are coreleased by depolarization, the genes coding for the processes that are rate limiting in the production of these neuromodulators can be differentially regulated.
- Research Organization:
- National Institute of Mental Health, Washington, DC
- OSTI ID:
- 5400012
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 83:5
- Country of Publication:
- United States
- Language:
- English
Similar Records
Tetrodotoxin-insensitive Na+ channel activator palytoxin inhibits tyrosine uptake into cultured bovine adrenal chromaffin cells
Selective inhibition of cholinergic receptor-mediated /sup 45/Ca++ uptake and catecholamine secretion from adrenal chromaffin cells by taxol and vinblastine
Related Subjects
ADRENAL GLANDS
AUTORADIOGRAPHY
DEXAMETHASONE
BIOLOGICAL EFFECTS
MESSENGER-RNA
CHEMICAL ACTIVATION
ALDOSTERONE
CATECHOLAMINES
CATTLE
ENKEPHALINS
GENE REGULATION
PROGESTERONE
TESTOSTERONE
ADRENAL HORMONES
ALDEHYDES
AMINES
ANDROGENS
ANDROSTANES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
CORTICOSTEROIDS
DOMESTIC ANIMALS
DRUGS
ENDOCRINE GLANDS
ENDORPHINS
GLANDS
GLUCOCORTICOIDS
HORMONES
HYDROXY COMPOUNDS
KETONES
MAMMALS
MINERALOCORTICOIDS
NEUROREGULATORS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
PHENOLS
POLYPEPTIDES
POLYPHENOLS
PREGNANES
PROTEINS
RNA
RUMINANTS
STEROID HORMONES
STEROIDS
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics