Figure 2: Time curves of T. spiralis molting process after exposure to progesterone (P4), estradiol (E2), and/or testosterone (T4). The parasites were cultured for 44 hours. Progesterone and estradiol had 35–50% of inhibitory effect on molting rate compared with control and testosterone. The maximum inhibitory effect was at 36 hr of culture. Each point represents the mean (SD) of 5 assays counting the number of molting larvae and the mean was obtained. . The hormone concentration was as follows: P4, 100 mM; E2, 50 nM, and T4, 50 nM.