Involvement of calmodulin and protein kinase C in cholecystokinin release by bombesin from STC-1 cells.
The mouse intestinal neuroendocrine tumor cell line STC-1 secretes cholecystokinin (CCK) and other hormones. We investigated the role of Ca2+, calmodulin (CaM), and protein kinase C (PKC) in the regulation of CCK release from STC-1 cells. Phorbol 12-myristate 13-acetate (TPA) significantly stimulated CCK release. Staurosporine significantly inhibited CCK release from STC-1 cells stimulated by TPA in a dose-dependent manner. The absence of extracellular calcium completely inhibited CCK release from TPA-stimulated STC-1 cells. Neurotensin did not stimulate CCK release from these cells. W-7, a CaM antagonist, reduced CCK release from STC-1 cells stimulated by bombesin in a dose-dependent manner. These findings suggest that CaM and PKC play an important role in the regulation of CCK release from STC-1 cells stimulated by bombesin.
Takahashi
A
A
Second Department of Internal Medicine, Showa University School of Medicine, Tokyo, Japan.
Tanaka
S
S
Miwa
Y
Y
Yoshida
H
H
Ikegami
A
A
Niikawa
J
J
Mitamura
K
K
D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002147:Calmodulin / Q000502:physiology*; D002766:Cholecystokinin / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007414:Intestinal Neoplasms / Q000378:metabolism*; D051379:Mice; D018358:Neuroendocrine Tumors / Q000378:metabolism*; D009496:Neurotensin / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D013449:Sulfonamides / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D002147:Calmodulin; D004791:Enzyme Inhibitors; D013449:Sulfonamides; D009496:Neurotensin; C017967:W 7; C034700:N-(6-aminohexyl)-1-naphthalenesulfonamide; D002766:Cholecystokinin; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D013755:Tetradecanoylphorbol Acetate; D001839:Bombesin