Cholinesterase activity in sea urchin early embryos may be correlated to the intracellular ion content.

The possible correlation between cholinesterase (ChE) activity and ion channels antagonist drug effects was studied in sea urchin early development, showing that ChE activity is different when cation channels are affected: generally, drugs maintaining channels in the open state, such as nicotine, cause an increased ChE activity, while antagonist drugs to receptors (such as curare, butx, ttx), cause a decreased activity, showing a direct effect of membrane depolarization on the enzymic activity, also in these non-neuromuscular stages.