MAMMOTROPE HETEROGENEITY IN THE PITUITARY-GLAND OF EUROPEAN FERRET, MUSTELA-PUTORIUS-FURO - AN IMMUNOELECTRONMICROSCOPIC STUDY

Employing the superimposition technique of electron-microscopic immuno cytochemistry ultrastructural heterogeneity of the mammotropes in the pituitary gland of the European ferret, Mustela putorius furo, was stu died. On the basis of the size of their secretory granules, the mammot ropes were classified into three subtypes, type-I, type-II and type-II I, which may correspond to different developmental or physiological st ates of a single cell type. Simultaneous study of mammotropes and soma totropes in several pairs of serial semithin sections demonstrated the occasional occurrence of bihormonal somatomammotropes/mammosomatotrop es which may represent a transitional stage of the progenitor stem-som atotrope during its differentiation into mammotrope; alternatively it may be a functional intermediate during the cross-transformation of so matotrope into mammotrope or vice versa.