The growth rate of the chlorotic, free-living flagellate Euglena gracilis var. bacillaris (streptomycin-bleached) is accelerated by androgenic, estrogenic, and adrenal steroid hormones at concentrations as low as 10-4 mg. steroid/l. of culture medium. Progesterone, pregnanediol, and cholesterol did not affect the growth rate of Euglena cells at any concentration used. The structural features necessary for the action of the steroid appear to be either a ketone or hydroxyl grouping at carbons 3 and/or 17 of the nucleus and an over-all planar configuration of the molecule. The data infer that in this growth-accelerating action any role other than that of a catalyst is unlikely for the steroid molecule.
ASJC Scopus subject areas
- Molecular Biology