1Department of Anatomy and neurobiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kagawa, 7610793, Japan
2Laboratory of Animal Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kagawa, 7610795, Japan
*Correspondence to: Yoshiki Takeuchi Department of Anatomy and Neurobiology Faculty of Medicine Kagawa University, 1750-1 Ikenobe Miki-cho, Kagawa 7610793 Japan
Online published on 14 December, 2011.
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 occasionally showed protrusions of membrane containing electron dense substance. The protrusions 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.
Large dense core vesicles, Apocrine-like structure, Posterior pituitary, Protrusion, Rat
