Pelvic Changes Occurring in Male Mice Receiving Large Amounts of Folliculin Benzoate

Abstract

The resorption of the pubic bones of the male pocket gopher has been induced experimentally by the administration of estrogenic hormone (Hisaw 1 ). In the guinea pig 2 hormones, one of follicular origin and one present in the blood of pregnant rabbits or in the corpus luteum, were necessary to induce a relaxation of the pelvic ligaments (Hisaw 2 ). In these species sexual dimorphism in the structure of the pelvis of matured animals exists. Males have the pubic bones well united by cartilage while the pubic bones of mature females have a ligamentous attachment.

This sexual dimorphism of the pubic symphysis was not noted in rats (Todd 3 ). The pubic bones were well and firmly attached at the symphysis on both males and females. Observations to be reported here indicate that large amounts of estrogenic hormone are effective in inducing changes in the symphysis of the mouse in which a sexual dimorphism of the pelvis also occurs.

Six male mice were given weekly subcutaneous injections of 500 international units of folliculin benzoate.∗ The injections were started at the time of weaning (28 days of age). The mice developed scrotal hernias after 6 to 8 weeks of treatment. One mouse was killed after 14 weeks of treatment and no change was noted in the pelvis. Five mice were removed after 19 to 28 weeks. At autopsy all presented greatly distended bladders, and 2 showed marked hydronephrosis and hydroureter. The urethras were greatly distended down to the region of the pubic symphysis. The region of the pubic symphysis was completely decalcified and ligamentous. The ligamentous band separated the pubic bones from 2 to 3 mm. The pelvis was easily movable as in the guinea pig at parturition.