Atrophy of Ovaries Transplanted to the Spleen in Unilaterally Castrated Rats; Proliferative Changes Following Subsequent Removal of Intact Ovary.

An ovary placed in the spleen of an animal that has one normal ovary undergoes atrophy that starts as early as 24 days after transplantation. Severe atrophy is reached before 55 days, and subsequent changes are minor. The degree of atrophy is almost as intense as that noted in the hypophysectomized castrate animal with an ovarian transplant in the spleen (2). The transplanted ovary shows no evidence of any type of response to the hormonal influence that has stimulated the ovary that remained in situ. Removal of the normal ovary introduces the hormonal imbalance that was present in the original tumor animals. The atrophic ovarian parenchyma in the spleen in these, as well as in the hypophysectomized animals previously reported, retained its growth potentials and responded to the hormonal forces by assuming the changes that characterized the development of the luteoma. The action of the atrophic ovarian parenchyma is reminiscent of malignant cell deposits that may remain dormant or quiescent for long periods and then, for some unknown reason, suddenly undergo growth.