Oestrogens and anti-oestrogens show dissociation between early uterine vascular responses and uterotrophic effects in mice.

The structure-activity relationships of various natural and synthetic oestrogens, anti-oestrogens and some other steroid hormones with respect to early uterine albumin accumulation (EAV) was studied in sprayed mice. The results were compared with the activity of these agents to produce a late anabolic response (LAR). The potency ranking order among the oestrogens with respect to EAV was found to be oestradiol-17 beta, greater than oestriol, greater than meso-hexoestrol, greater than erythro-deoxyhexoestrol, greater than ent-oestradiol-17 beta, greater than (-)methallenestril phenol. Generally the oestrogens were much more potent with respect to EAV than LAR. No correlation was found when the ability to promote EAV and LAR was compared. Among other agents tested for effect on the EAV, progesterone, the synthetic progestogen, DU-41165 and the anti-hormones MER-25 and U-11100A (nafoxidine) showed no effect. However, hydrocortisone diminished EAV, while dihydrotestosterone increased EAV substantially.