Acetylcholinesterase Activity of Insect Cells, in Particular Flesh Fly Cells, Cultured In Vitro

The activity of acetylcholinesterase (AChE) of cultured insect cells was measured. A mosquito cell line, NIAS-AeAl-2, showed the highest activity, and a flesh fly cell line, NIH-SaPe-4, the second highest, whereas two Drosophila cell lines showed no activity. Several lepidopteran cell lines showed low activity, and some cabbage armyworm cell lines and silkworm cell lines did not show the activity. In the culture of the NIH-SaPe-4 cells, activity was low right after the seeding of cells. It increased during the first two days of the culture, and then decreased. AChE activity appeared, and increased in the culture media as the culture progressed. When eserine sulfate, an inhibitor of AChE, was incorporated into the culture medium, the growth of the NIH-SaPe-4 cells was not affected by the AChE activity of the cells decreased. The AChE of the NIH-SaPe-4 cells showed strong affinity to acetylthiocholine compared with s-butylthiocholine.