Influence of prolactin on pinealocytes of the mouse with hereditary hypopituitarism: A quantitative ultrastructural study

Abstract The influence of prolactin on the ultrastructure of pinealocytes was examined morphometrically in Snell dwarf mice ( dw / dw ). Ultrastructural features characteristic of a diminished activity of the pinealocytes were observed in dwarf mice as compared with phenotypically normal controls. Administration of prolactin induced morphological signs of activation of the mutant pinealocytes, especially in regard to the ependymal-like secretory process.