[Morphological characteristics of the structures delimiting the residual cavity of the hypophysis in rats after electrocoagulation of the median eminence of the hypothalamus].

By means of light and electron microscopy it has been shown that the remnant cavity of the hypophysis of intact and sham-operated rats on the side of the intermedial lobe is restricted with a continuous layer of epithelial cells with a well pronounced basal membrane. On the side of the frontal lobe the covering epithelium has peculiar "fenestra" through which adenocytes have free contacts with the remnant cavity. After electrocoagulation of the rostral area of the medial eminence, especially in remote postoperative terms, the remnant cavity enlarges up to gigantic size, contains a great amount of colloid, erythrocytes, fragments of cells of the anterior lobe of the hypophysis and secretory granules. The anterior epithelium is lacking on considerable areas and hence adenocytes are disposed in the cavity directly. All their organoids are preserved though a little changed, the cytomembrane is absent. On the apical surface of the posterior epithelium there appear large cytoplasmic protrusions which having separated enter the remnant cavity. The main provider of the "raw material" for colloid is likely to be the anterior lobe of hypophysis.