Characteristics of inositol polyphosphate metabolism in cultured adrenal chromaffin cells.
1. Nicotine, high K+ and maitotoxin caused the inositol polyphosphate accumulation concomitant with 45Ca2+ uptake. 2. Angiotensin II (Ang II) and ATP induced the inositol polyphosphate accumulation without 45Ca2+ uptake. 3. Nifedipine-treatment and Ca(2+)-deprivation inhibited the high K(+)-induced inositol polyphosphate accumulation but failed to inhibit the Ang II-induced inositol polyphosphate accumulation. 4. 12-O-tetradecanoylphorbol-13-acetate inhibited the Ang II-induced inositol polyphosphate accumulation but failed to inhibit the high K(+)-induced one. 5. These results suggest that the formation of inositol polyphosphates may be regulated by two mechanisms, i.e. Ca2+ uptake-dependent mechanisms represented by high K+, and Ca2+ uptake-independent mechanisms represented by Ang II.
Sasakawa
N
N
Department of Pharmacology, Keio University School of medicine, Tokyo, Japan.
Nakaki
T
T
Kato
R
R
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002132:Calcium Radioisotopes; D002417:Cattle; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004759:Enterochromaffin Cells / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism* / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology; D013268:Stimulation, Chemical; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D002132:Calcium Radioisotopes; D007295:Inositol Phosphates; C081655:inositol-1,3,4,5-tetrakisphosphate; C013571:inositol pentaphosphate; D015544:Inositol 1,4,5-Trisphosphate; D009543:Nifedipine; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium