FIG. 1.

Dose effect of calpain inhibitor II on the excystment process. About 2,000 cysts were incubated with food and inhibitor (see text for details). The effect was evaluated by counting cysts and vegetative cells in three samples taken from each experiment (i.e., for each inhibitor concentration), and the excysting rate is expressed as the percentage of excysted vegetative cells in each experiment. Total inhibition is observed with a 10 μM inhibitor concentration; this result was confirmed in all experiments, and the 10 μM value was retained to test the different inhibitors. Identical results were obtained with the other active inhibitors (data not shown).