Functional differentiation of cells in the anterior and intermediate pituitary glands - Immunohistochemical studies.

Abstract

Immunohistochemical studies have demonstrated that in the adult rat and human anterior pituitary glands that one cell might be devoted to the production of one hormone with the exception of FSH and LH. In addition, the intermediate lobe cells are exclusively positive for ACTH. In studies of rat and human fetal pituitary glands, ACTH was the first hormone to appear in both anterior and intermediate cells, followed by other hormone-producing cells. As the hypothalamic tropic hormones appear later than the corresponding pituitary hormones, it was considered that the pituitary cells might differentiate toward hormone production independently of the hypothalamus and that hypothalamic tropic factors might be necessary to maintain or promote hormone production. This is supported by studies on human anencephalic pituitaries and cultured rat pituitary primordial cells.