Author(s): Jun-Qian Liu, Takanori Miki, Katsuhiko Warita, Ken-ichi Ohta, Shingo Suzuki?Tomiko Ya-kura, Motoki Tamai, Yoshiki Matsumoto, Yoshiki Takeuchi
Secretion manner from neurosecretory terminals was revalued in the rat posterior pituitary (PP). 1 μm-thick sections stained with toluidine blue showed various structures in the PP, such as fibers, pituicytes, capillaries and vascular spaces. Although a lot of terminals containing small clear vesicles and large dense core vesicles (LDCV) were observed at the electron microscopic level, morphological changes associated with exocytosis were never found around the membrane of terminals. It was of particular interest that terminals occa-sionally showed protrusions of membrane containing electron dense substance. The protru-sions were frequently torn from the terminals and were floating in the vascular space. Some of LDCV were apparently contained in the protrusions. The present findings provided the morphological evidence for the secretion manner from secretory terminals in the PP which was quite similar to apocrine-like structure.