An electron microscopical study of calcitonin gene-related peptide-like immunoreactive innervation of the anterior pituitary in the dog.
Our previous studies have demonstrated the presence of a considerable number of substance P-, calcitonin gene-related peptide (CGRP)-, and galanin-like immunoreactive (LI) nerve fibers in the anterior pituitary in several mammalian species. The present study investigated the ultrastructure of the CGRP-LI innervation of this gland in the dog. The CGRP-LI nerve fibers were unmyelinated, with a wealth of varicosities containing both small clear synaptic vesicles and large dense-cored vesicles. They were found to be in direct contact with every cell type of the anterior pituitary. However, only on corticotropes and somatotropes were CGRP-LI synaptic contacts identified. Most of them were asymmetrical in type. Occasional symmetrical synaptic contacts were also found. It is considered likely that direct neural factors may play a role in the regulation of the anterior pituitary.
Ju
G
G
Department of Neurobiology, Fourth Military Medical University, Xi'an, People's Republic of China.
Zhang
X
X
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000276:immunology / Q000378:metabolism*; D004285:Dogs; D008297:Male; D016253:Microscopy, Immunoelectron; D009412:Nerve Fibers / Q000276:immunology / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure*; D016610:Tissue Embedding
D015740:Calcitonin Gene-Related Peptide