Surface topography of cultured anterior pituitary cells of the rat.

Anterior pituitary cells of the adult rat were studied by scanning electron microscopy after 3, 6 and 8 days in culture. Epithelial (parenchymal) cells and fibroblasts could be differentiated by their characteristic cell surface structures and by their associations with each other. The surface of solitary and grouped epithelial cells is uneven and rich in smaller or larger blebs, wrinkles and microvilli. A few solitary cilia were found on the surface of some cells. The individual cells forming epithelial cell groups adhere to each other with numerous, parallel, slender extensions. The fibroblasts found in monolayers have extensions with various lengths contacting other cells or the inert substratum. Microvilli arise in various frequency from their smooth surface. Transmission electron microscopy confirmed the presence of the surface structures detected in the scanning electron microscope.