抄録
Previously Fujii (1957) has confirmed that prolactin from the anterior pituitary played a main role in the lactation. This fact was also supported by the results of prolactin determinations in the human urine (Shimizu, 1958) and in the anterior pituitary of the rat (Okamoto, 1958). The present investigation was attempted in order to support this fact from the view of numerical changes in the anterior hypophysial cells of the female rat. Recently it has been demonstrated that the pituitary separated from the hypothalamic control released prolactin. In the present investigation grafted pituitary tissue in the spleen of the rat was histologically studied. The present investigation demonstrated that α-cell numbers flactuated in accordance with prolactin content in the anterior pituitary. Especially in the lactating period both reached to the maximum. This fact suggested that α-cell should be a source of prolactin. Consequently, influences of various conditions on the lactation and physiological function of the pituitary graft were illustrated from the view of numerical changes of α-cell in the anterior pituitary.
