[Hypophysian and ovarian function following a single postnatal estradiol injection. II. Studies on rats in parabiosis (author's transl)]. / Hypophysen- und Ovarienfunktion nach einer postnatalen Oestradiolinjektion II. Untersuchungen an Ratten in Parabiose.

We have studied the functioning of the axis hypophysis-ovary in rats which had received an injection of 100 microgram estradiol benzoate, in the first days of life. The experimental method was the parabiosis of two animals (male or female, normal or estrogenized, intact or spayed) in different combinations. We established that estrogenization damages the hypopysis as well as the ovary to such a degree that both glands cease to function normally. --Injected gonadotrophins can procude luteinization of estrogenized ovaries. This effect, however, appears only as a direct consequence of hormone administration. Exogenous gonadotrophins can never trigger cyclical function of estrogenized ovaries.

Chimeric analysis of hemopoietic cells after cross-sex parabiosis.

Anemia or polycythemia was induced in male rats. These males were conjugated with healthy, untreated female litter mates by FANG'S method of aortic parabiosis that resulted in complete cross circulation of blood between the two animals. The sex chromosomes of cells in erythropoiesis in various hemopoietic organs were examined in the treated male animals. The anemic parabionts indicated sharp increases in chimerical rates with erythroid marrows being evident. Polycythemic parabionts indicated marked decreases in chimerical rates with evidence of myeloid marrows. These findings suggested that the so-called stem cells in peripheral blood of the female parabiont migrated to the bone marrow of the male partner and that these migrating cells differentiated to erythroblast. The possible relationships between erythropoiesis and other cell proliferations in the hemopoietic organs are discussed.