8 alpha-Estra-1,3,5(10)-triene-1,3, 17 beta-triol as a special type of estrogen having a high vaginotrophic activity and a low uterotrophic activity in castrated mice.
The vaginotrophic and uterotrophic activities of 1-OH-8-alpha-E2 and its acetate in comparison with E2 and E3  were assessed on the basis of the effect on weights, water/fat-and RNA/DNA-contents of mouse vagina and uterus. The multiple doses of 8 alpha-steroids or E3 sufficient to achieve a maximal effect on the vagina were not enough to stimulate the uterus fully. At various periods of time after multiple injections, 1-OH-8 alpha-E2 acetate was found to have a higher vaginotrophic potency than the uterotrophic potency, when compared with E2 as a standard. The study on the time course of organ response to 8 alpha-steroids, E2 and E3 after a single injection of daily dose, being equipotent when injected one daily for 3 days, demonstrated that 1-OH-8-alpha-E2 and E3 were less vaginotrophic and uterotrophic than E2 and had a short duration of action. 1-OH-8 alpha-E2 acetate in comparison with  E2 produced a long-lasting vaginotrophic effect and an early regressing uterotrophic effect. It can be confirmed that 8 alpha-steroids, like E3, are a special type of estrogen having a high vaginotrophic activity and a low uterotrophic activity.
D000818:Animals; D002369:Castration; D004247:DNA / Q000378:metabolism; D045166:Estradiol Congeners / Q000494:pharmacology*; D005260:Female; D050356:Lipid Metabolism; D051379:Mice; D009929:Organ Size / Q000187:drug effects; D009928:Organ Specificity; D012313:RNA / Q000378:metabolism; D013329:Structure-Activity Relationship; D014599:Uterus / Q000187:drug effects / Q000502:physiology*; D014621:Vagina / Q000187:drug effects / Q000502:physiology*
D045166:Estradiol Congeners; D012313:RNA; D004247:DNA