Effect of Anol and Dihydrotheelin on Mammogenic Activity of Pituitary Gland of Rabbits. ∗

It has been shown that estrogen stimulates the production of a mammogenic hormone entity by the anterior pituitary which is directly responsible for the growth of the mammary gland. 1 , 2 More recently, Gomez and Turner 3 reported that anol stimulated the growth of the mammary glands of ovariectomized rabbits, rats and male mice and suggested that like estrogen, the action of anol upon the mammary gland is probably indirect by way of the pituitary gland. It is interesting, therefore, to determine the effect of various estrogens and chemical substances having the dual activity of estrogenesis and carcinogenesis upon the mammogenic activity of the anterior pituitary gland. In the present communication, the effect of anol and dihydrotheelin is reported.

A group of 8 young adult virgin female rabbits were each given by subcutaneous injection once daily 0.1 mg of anol‡ for 25 days: a second group of 10 rabbits with 20 rat units of dihydrotheelin daily for 25 days and a third group of 6 rabbits with 0.1 mg of anol and 20 rat units of dihydrotheelin simultaneously once daily for 25 days. All injected animals were sacrificed 24 hours after the last injection. In addition, a group of 24 young adult virgin females and another of 10 young adult male rabbits were sacrificed as control donors. The pituitaries of animals from each group were combined, weighed and assayed as a unit for mammogenic activity by the male mice technic described by Lewis, et al. 4 According to this method of assay, a mouse unit of mammogen is defined as the minimum amount of pituitary tissue or extract which when injected once daily over a period of 6 days will produce definite mammary growth stimulation of one or more glands of 50 ± 10% of 10 male mice each weighing 10 to 25 g.