Sex steroid content and metabolism in Trichostrongylus colubriformis (Nematoda).

Testosterone, progesterone and cholesterol were found in mixed sexes of the nematode Tricho- strongylus colubriformis from goats, according to thin-layer, gas-liquid and high-performance liquid chroma- tography. The structure of these steroids was confirmed by proton nuclear magnetic resonance and mass spec- troscopy. Melting points of the worms' steroids were similar to authentic standards of the steroids. Estradiol was not detected in worms from either goat sex. Cholesterol was about 0.08% of the worms' dry weight in helminths from either sex of host. Testosterone was 0.02% of the dry weight when worms were taken from male goats, but only 0.005% from female goats. Progesterone was not detected in worms from male goats, but was 0.005% of the dry weight of helminths from female hosts. Incubation of a worm preparation with tritiated steroids showed that progesterone was converted to 17-a-hydroxyprogesterone, based on retention during ra- dioactive thin-layer and gas-liquid chromatography, and co-crystallization. Testosterone, cholesterol and 17-,/- estradiol were not metabolized.