Down-regulation of protein kinase C activity preferentially attenuates high K(+)-stimulated tyrosine hydroxylase activity in adrenal chromaffin cells cultured with insulin-like growth factor-I.
Neurosci Lett
; 201(2): 99-102, 1995 Dec 08.
Article
in En
| MEDLINE
| ID: mdl-8848250
ABSTRACT
The purpose of this study was to determine whether the loss of protein kinase C (PKC) from adrenal chromaffin cells affected the enhancement of high K(+)- and forskolin-stimulated tyrosine hydroxylase (tyrosine 3-monooxygenase, EC 1.14.16.2) activity observed in cells treated with insulin-like growth factor-I (IGF-I). Forskolin-stimulated tyrosine hydroxylase activation was not affected by down-regulation of PKC. High K(+)-stimulated tyrosine hydroxylase activity decreased substantially after treating the cells for approximately 18 h with active, but not inactive, phorbol ester (300 nM). After down-regulation of PKC, high K(+)-stimulated tyrosine hydroxylase activity in cells cultured with IGF-I decreased by 61 +/- 5% (n = 14) compared to 36 +/- 8% (n = 14) in cells cultured without IGF-I. These data suggest that PKC is required for the enhancement of high K(+)-stimulated tyrosine hydroxylase activity observed with IGF-I treatment.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Potassium
/
Tyrosine 3-Monooxygenase
/
Protein Kinase C
/
Insulin-Like Growth Factor I
/
Chromaffin System
Limits:
Animals
Language:
En
Journal:
Neurosci Lett
Year:
1995
Document type:
Article
Affiliation country:
United States