INDUCTION OF MUSCARINIC RECEPTOR SUBTYPES IN MONOCYTIC MACROPHAGIC CELLS DIFFERENTIATED FROM EOL-1 CELLS

We demonstrated that eosinophilic leukemia cell line-1 (EoL-1 cells) d ifferentiated into monocytic/macrophagic cells by a treatment with int erferon-gamma. Muscarinic receptor mRNA was not detected in untreated EoL-1 cells, and the cytosolic concentration of Ca2+ ([Ca2+](i)) did n ot rise either in these cells. Interestingly, when EoL-1 cells were tr eated with interferon-gamma, mRNAs for muscarinic M(3) and M(5) recept ors could be detected in these cells, along with an increase in [Ca2+] (i) and chemotaxis induced by carbachol that could be blocked with 4-d iphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) and pirenzepine. These data support the functional importance of muscarinic M(3) and M (5) receptors in monocytic/macrophagic cells differentiated from EoL-1 cells. This model also provides evidence of a significant functional interaction between muscarinic M(3) and M(5) receptors.