title: Inhibition of muscarinic receptor-mediated Ca27#x002B;mobilization by phorbol 12-myristate 13-acetate in chick embryo cells.
abstract: A muscarinic cholinergic receptor is present on undifferentiated cells of the chick embryo. Stimulation of the muscarinic receptor with muscarinic agonists triggers intracellular Ca2#x002B;mobilization. Here, we investigate the effect of phorbol 12-myristate 13-acetate (PMA) on the muscarinic receptor-mediated Ca2#x002B;mobilization, which is monitored in cell suspensions of chick embryos of stage 24 by chlorotetracycline fluorescence. PMA inhibits the Ca2#x002B;mobilization in a time-dependent and concentration-dependent manner without changing the ED50of acetylcholine. The concentration of PMA that gives halfmaximal inhibition is 3.1×10-9M PMA.
authors.affiliation: Anatomisches Institut der Universität Tübingen, Österbergstraße 3, D-7400, Tübingen, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Schmidt
authors.affiliation: Anatomisches Institut der Universität Tübingen, Österbergstraße 3, D-7400, Tübingen, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Oettling
authors.affiliation: Anatomisches Institut der Universität Tübingen, Österbergstraße 3, D-7400, Tübingen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Drews
keywords: Calcium; Chick embryo; Morphogenesis; Muscarinic receptor; Phorbol ester