Responsiveness of Human Fetal Pituitary to Hypothalamic Hormones in vitro

抄録

The pituitary of the human fetus in the second trimester of pregnancy contains a considerable amount of LH and HGH. The average LH and HGH contents of the pituitaries were found to be 3.4IU/gland and 2.3μg/gland, respectively. The pituitary content and concentration of HGH increased significantly as the fetal age advanced, although there were no remarkable changes in the pituitary content of LH. The pituitary incubated in vitro secreted LH, FSH and HGH into the medium. The addition of rat hypothalamic extract into the medium increased the release of LH and HGH by the pituitary. Synthetic LH-RH also enhanced the pituitary release of LH and FSH in vitro. However, in the pituitaries of the fetuses younger than the 16th weeks of gestation the secretion of LH and FSH in vitro was not stimulated by the addition of synthetic LH-RH. The results demonstrate that the anterior pituitary of the human fetus is responsive to hypothalamic releasing factors in vitro at least by the 19th weeks of fetal age.