MULTIPOTENTIAL PITUITARY-CELLS THAT CONTAIN ADRENOCORTICOTROPIN (ACTH) AND OTHER PITUITARY-HORMONES

Anterior pituitary cells that contain adrenocorticotropin (ACTH) are morphologically and functionally heterogeneous. Immunolabeling has identified stellate subtypes with scattered or peripherally arranged granules, and ovoid or irregularly shaped cells with a denser accumulation of granules, which overlap morphologically with other cell types such as small gonadotropes or thyrotropes. Dual cytochemical labeling studies on the same or serial fields have identified cells that store ACTH with LH, FSH, TSH, or prolactin. Evidence is presented to suggest that they are multipotential cells with the capacity to augment corticotropes or one of the other cell populations.