IMMUNOHISTOCHEMICAL DEMONSTRATION OF ESTROGEN RECEPTOR IN HUMAN ADENOHYPOPHYSIAL CELLS AND PITUITARY ADENOMAS

Abstract

The localization of estrogen receptor in normal human pituitary glands and in human pituitary adenomas was investigated using immunoreactivity to polyclonal antibodies against human estrogen receptor in five normal pituitary samples and 45 specimens of pituitary adenoma. The relationship between the expression of estrogen receptor and the production of pituitary hormones was clarified using double immunohistochemical staining. Estrogen receptor was present in both cells of normal pituitary glands and pituitary adenomas. In normal pituitary glands, adenohypophysial cells were immunoreactive for estrogen receptor irrespective of hormone production. In pituitary adenomas, 35 of 45 specimens showed positive immunoreactivity to estrogen receptor. All cases of lactotroph cell adenoma, corticotroph cell adenoma, gonadotroph cell adenoma, and plurihormonal adenoma with clinical signs of acromegaly showed positive immunoreactivity to estrogen receptor. The present study demonstrates the intracellular localization of estrogen receptor in normal adenohypophysial cells of human pituitary glands and in human pituitary adenomas.