Modulation of L-type Ca2+ channel currents by various protein kinase activators and inhibitors in rat clonal pituitary GH3 cell line
The Korean Journal of Physiology and Pharmacology
;
: 139-146, 2001.
Article
in English
| WPRIM
| ID: wpr-728224
ABSTRACT
L-type Ca2+ channels play an important role in regulating cytosolic Ca2+ and thereby regulating hormone secretions in neuroendocrine cells. Since hormone secretions are also regulated by various kinds of protein kinases, we investigated the role of some kinase activators and inhibitors in the regulation of the L-type Ca2+ channel currents in rat pituitary GH3 cells using the patch-clamp technique. Phorbol 12,13-dibutyrate (PDBu), a protein kinase C (PKC) activator, and vanadate, a protein tyrosine phosphatase (PTP) inhibitor, increased the Ba2+ current through the L-type Ca2+ channels. In contrast, bisindolylmaleimide I (BIM I), a PKC inhibitor, and genistein, a protein tyrosine kinase (PTK) inhibitor, suppressed the Ba2+ currents. Forskolin, an adenylate cyclase activator, and isobutyl methylxanthine (IBMX), a non-specific phosphodiesterase inhibitor, reduced Ba2+ currents. The above results show that the L-type Ca2+ channels are activated by PKC and PTK, and inhibited by elevation of cyclic nucleotides such as cAMP. From these results, it is suggested that the regulation of hormone secretion by various kinase activity in GH3 cells may be attributable, at least in part, to their effect on L-type Ca2+ channels.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Phosphotransferases
/
Protein Kinases
/
Colforsin
/
Protein Kinase C
/
Protein-Tyrosine Kinases
/
Vanadates
/
Phorbol 12,13-Dibutyrate
/
Cell Line
/
Adenylyl Cyclases
/
Protein Tyrosine Phosphatases
Limits:
Animals
Language:
English
Journal:
The Korean Journal of Physiology and Pharmacology
Year:
2001
Type:
Article
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