Discrimination of histamine H1 and muscarinic receptor-mediated signalling pathways by phorbol ester in human astrocytoma cells.
1. Histamine H1 receptor-mediated signalling was compared with muscarinic receptor-mediated signalling in 1321N1 human astrocytoma cells. 2. Short-term (2 min) treatment of cells with phorbol 12-myristate 13-acetate (PMA) resulted in a reduction of increases in intracellular Ca2+ ([Ca2+]i) induced by carbachol or histamine. 3. Carbachol-induced increases in [Ca2+]i were 10-fold more sensitive to PMA than the histamine-induced increases. 4. When cells were treated with PMA for 48 or 72 h (long-term treatment), protein kinase C (PKC) was down-regulated and PMA did not inhibit carbachol-induced increases in [Ca2+]i. 5. Histamine-induced increases in [Ca2+]i were significantly reduced by long-term treatment with PMA. 6. These findings suggest that the signalling pathways mediated by histamine H1 and muscarinic receptors can be distinguished by using PKC in 1321N1 human astrocytoma cells.
Kurita
M
M
Department of Neuropsychiatry, Fukushima Medical University School of Medicine, Japan.
Mashiko
H
H
Ogata
M
M
Kumasaka
T
T
Niwa
S
S
Nakahata
N
N
Takano
S
S
Nakanishi
H
H
D001254:Astrocytoma / Q000201:enzymology / Q000378:metabolism*; D001932:Brain Neoplasms / Q000201:enzymology / Q000378:metabolism*; D002217:Carbachol / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology*; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D018721:Muscarinic Agonists / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D011969:Receptors, Histamine H1 / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D002273:Carcinogens; D002614:Chelating Agents; D018721:Muscarinic Agonists; D011969:Receptors, Histamine H1; D011976:Receptors, Muscarinic; D004533:Egtazic Acid; D006632:Histamine; D002217:Carbachol; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate