目的　观察ERα和 β两个亚型在大鼠垂体前叶的表达及两者是否共存。 　方法　用种属特异性抗体 (兔抗大鼠ERα和羊抗大鼠ERβ抗体 )进行免疫组织化学染色。 　结果　ERα免疫反应物质位于细胞核内 ,其阳性细胞主要分布于垂体前叶和后叶 ,中间叶极少。ERβ免疫反应物质位于胞浆和胞膜 ,其阳性细胞主要分布于垂体前叶和中间叶 ,后叶不表达。ERα和ERβ可共存于同一细胞。　结论　ERα和ERβ在大鼠垂体前叶分布不同 ,但部分细胞有共存 ,提示两者在介导雌激素的作用中有不同功能 Objective To observe the expression of ERα and β in the anterior pituitary of rats and their co-existence. Methods Immunohistochemical staining was performed with species-specific antibodies (rabbit anti-rat ERα and goat anti-rat ERβ antibody). Results The ERα immunoreactive substance located in the nucleus, the positive cells were mainly distributed in the anterior pituitary and posterior pituitary, with few intermediate leaves. ERβ immunoreactive substance is located in the cytoplasm and membrane, the positive cells are mainly distributed in the anterior pituitary and middle leaves, but not in the posterior lobe. ERα and ERβ can co-exist in the same cell. Conclusion The distribution of ERα and ERβ in the anterior pituitary of rat is different, but some cells coexist, suggesting that both have different functions in mediating estrogen