Increased adhesion of Chinese hamster ovary cells to substratum by cholera enterotoxin.

A new, simple assay method using Chinese hamster ovary cells was devised for cholera enterotoxin. The effect of the cholera toxin was measured by an increase in cell adhesion to the substratum. The increase was dependent on the concentration of the toxin used and was effective for a longer period of time than that of adhesion increased by dibutyryl cyclic adenosine monophosphate and theophyline. There was a delay of about 60 min before the increase in adhesion, using the toxin, appeared, whereas the increase caused by dibutyryl cyclic adenosine monophosphate appeared almost at once.