title: Increase in activity of acetylcholinesterase by 20-OH-ecdysone in a Chironomus tentans cell line.
abstract: An epithelial cell line from Chironomus tentans exhibits acetylcholinesterase activity (specific activity 0.05-0.2 nkat/mg protein), which rises 30- to 40-fold after addition of 10-6M 20-OH-ecdysone. The first visible increase occurs after 4 days of incubation with hormone. The enzyme has an apparent Kmof 2.3±0.2×10-4M for acetylthiocholine iodide as substrate and is inhibited by eserine and BW284 C51 (50% inhibition at 5×10-7M for both inhibitiors) as well as by high concentrations of substrate, but not by tetraisopropylpyrophosphamide. The sensitivity against inhibitors is the same in extracts from hormone-treated cells and from controls. The cholinesterase activity correlates with morphological changes (shape and cell arrangement) and is indepenent of neuronal differentiation. We therefore propose a function for this activity during morphogenesis.
authors.affiliation: Abteilung für Parasitologie an der Universität Düsseldorf, Universitätsstrasse 1, D-4000, Düsseldorf l, Germany.
authors.forename: Margarethe
authors.initials: M
authors.lastname: Spindler-Barth
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: Ulrich
authors.initials: U
authors.lastname: Drews
authors.affiliation: Lehrstuhl für Hormon- und Entwicklungsphysiologie, Universität Düsseldorf, Universitätsstrasse 1, D-4000, Düsseldorf l, Germany.
authors.forename: Klaus -Dieter
authors.initials: K-
authors.lastname: Spindler
keywords: Acetylcholinesterase; Chironomus cell line; Ecdysteroid