Inositol trisphosphate accumulation by high K+ stimulation in cultured adrenal chromaffin cells.
Stimulation with high K+ (KCl, 56 mM) of myo-[3H]inositol-prelabelled cells increased Ca2+ uptake and [3H]inositol trisphosphate (IP3) accumulation in a concentration-dependent manner. Nifedipine, a Ca2+ channel antagonist, inhibited high K+-induced [3H]IP3 accumulation and 45Ca2+ uptake with a similar potency. Furthermore, ionomycin (1 microM), a Ca2+ ionophore, also induced 45Ca2+ uptake and [3H]IP3 accumulation. These results indicate the existence of the Ca2+ uptake-triggered mechanism of IP3 formation in cultured adrenal chromaffin cells.
D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D004987:Ethers / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000378:metabolism*; D015759:Ionomycin; D009543:Nifedipine / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology*; D013403:Sugar Phosphates / Q000378:metabolism*
D004987:Ethers; D007295:Inositol Phosphates; D013403:Sugar Phosphates; D015759:Ionomycin; D015544:Inositol 1,4,5-Trisphosphate; D009543:Nifedipine; D011188:Potassium; D002118:Calcium