Development of Tumors in the Rat Ovary After Transplantation into the Spleen.

It has been shown by Golden and Sevring-haus 1 that rats in which the ovaries have been transplanted to the mesentery remain anestrous, owing to inactivation in the liver (previously reported by Zondek 2 ) of the estrogen thus secreted into the portal circulation. Thereafter for approximately 11 months

This phenomenon was more extensively studied by G. R. Biskind 3 , 4 , 5 , 6 using pellets of crystalline steroids implanted in another organ in the portal circulation, the spleen. Castrate rats on a complete diet with pellets of estrone or estradiol thus implanted likewise remained anestrous. During the course of an investigation on the effect of nutritional deficiency on the estrogen-inactivating function of the liver,^7-9 M. S. Biskind and Shelensyak 10 demonstrated that animals with one ovary removed and the other transplanted to the spleen showed no estrual reactions so long as the diet was adequate to maintain the functional integrity of the liver.

This observation seemed to provide an excellent means of ascertaining the effect on the ovary of protracted stimulation by the pituitary, under conditions in which the latter organ is freed from the normal inhibitory action of the secreted estrogen.

According, a series of adult female rats of the Sherman strain were castrated and one ovary was transplanted to the spleen† After an interval of approximately 2 weeks, all the animals had daily vaginal smears to rule out those with vascularized adhesions that permitted ovarian estrogen to by-pass the portal circulation. Those showing estrous reactions were discarded. The others were maintained on a complete diet§ thereafter for approximately 11 months. At the end of this time 9 animals remained; they were again smeared daily over a period of 3 weeks to determine whether any estrogen was reaching the systemic circulation.