An Immunoelectron Microscopic Study of Peptide Substances in the Rat Neurohypophysis

Overview

Journal J Tongji Med Univ

Specialty General Medicine

Date 1989 Jan 1

PMID 2474669

Authors

C G Zhu

A Q Chen

Q Y Liu

Y Wei

X L Peng

Affiliations

Soon will be listed here.

Abstract

The ultrastructural localization of peptide substances, such as vasopressin (VP), substance P (SP), enkephalin (ENK) and somatostatin (SRIF), and the distribution of peptidergic nerves in rat neurohypophysis were studied by immunoelectron microscopy. The results show that VP, SP, ENK and SRIF immunoreactive products are located in large granular vesicles (110-150 nm in diameter), at the periphery of microvesicles and on the outer membrane of mitochondria. The VP-, SP-, ENK- and SRIF- containing nerve fibers are distributed at the periphery of capillaries and in the vicinity of pituicytes. VP- and ENK-positive nerve terminals form axo-axonic synapses with negative terminals. VP- and ENK-terminals are pre- or postsynaptic elements. Axo-axonic synapses formed by two SRIF- positive terminals were also found. In addition, ENK- and SP-positive terminals with pituicytes form synaptoid structures respectively. The authors have discovered VP-positive pituicytes for the first time.

References

Loesch A . The neurosecretory axons in the neurohypophysis of the rat: an electron microscopic study. J Ultrastruct Res. 1981; 77(3):344-53. DOI: 10.1016/s0022-5320(81)80030-5. View

Wittkowski W, Brinkmann H . Changes of extent of neuro-vascular contacts and number of neuro-glial synaptoid contacts in the pituitary posterior lobe of dehydrated rats. Anat Embryol (Berl). 1974; 146(2):157-65. DOI: 10.1007/BF00315592. View

BARGMANN W, Knoop A . [Electron microscopic observations of the neurohypophysis]. Z Zellforsch Mikrosk Anat. 1957; 46(2):242-51. View

Van Leeuwen F . Enkephalin in the rat neural lobe: immunocytochemical evidence for its presence within synaptic elements on pituicytes. Prog Brain Res. 1982; 55:253-64. DOI: 10.1016/S0079-6123(08)64202-8. View

Rabhi M, Onteniente B, Kah O, Geffard M, Calas A . Immunocytochemical study of the GABAergic innervation of the mouse pituitary by use of antibodies against gamma-aminobutyric acid (GABA). Cell Tissue Res. 1987; 247(1):33-40. DOI: 10.1007/BF00216544. View