抄録
Male fetal rats were castrated in utero on the 21st day of pregnancy. Twenty-four hours after the operation, changes of 3H-leucine uptake of hypothalamic nuclei were examined autoradiographically. Leucine uptake in cell bodies of neurons of the arcuate nucleus was enhanced significantly as compared with that in sham-operated control fetuses. However, the uptake in cell bodies of neurons of the supraoptic, paraventricular and ventromedial nuclei did not show any significant change following castration. Since it is known that a gonadotropin releasing factor is a polypeptide and localized to the arcuate nucleus and median eminence, the increase of leucine uptake in cell bodies of the arcuate nucleus seems to suggest the production of a gonadotropin releasing factor as a result of castration. From these findings, it is suggested that the hypothalamic-pituitarytesticular axis begins to function before birth.
