Figure 2: Progesterone stimulates worm growth in a concentration-independent pattern (a), reaching its maximum effect at 20 day of in vitro culture (b). In contrast, RU486 inhibits worm development with the lowest concentration (0.06 M) (a) and during the whole culture time (b). Progesterone-treated parasites were motile and undamaged on the culture plate, typically distinct to those treated with RU486. Worm length was considered as the addition (mm) of scolex, neck, and strobila. In the concentration-response curves (panel a), cysticerci treated with vehicle are referred as concentration zero. Data are represented as mean SD; .