Antagonists to cholinergic receptors increase the frequency of binuclear V79 Chinese hamster cells. A mechanism for induction of aneuploidy

Abstract

V79 Chinese hamster cells were found to produce significant amounts of acetylcholine. Asynchronously growing V79 cells were treated with five different antagonists to cholinergic receptors: atropine and scopolamine, which are inhibitors of muscarinic receptors, and mecamylamine, d-tubocurarine and α-bungarotoxin, which are inhibitors of nicotinic receptors. All compounds caused a slight but significant increase of the frequency of binuclear interphase cells and also of the frequency of cells in late telophase and early G 1 that had not completed cleavage. In addition, hemicholinium-3, a specific choline uptake antagonist, inhibited cleavage. Taken together, it seems reasonable to hypothesize that acetylcholine and its receptors take part in the regulation of cleavage in these cells. As binuclear cells are prone to aberrant spindle functions in following mitoses, inhibition of cleavage may constitute a risk for generation of cells with highly aberrant chromosome numbers.