THE RELATIONSHIP OF GALANIN IMMUNOREACTIVE NERVE-FIBERS TO GLANDULAR CELLS IN THE ANTERIOR-PITUITARY IN THE MONKEY

The anterior pituitary is known to be regulated by hypothalamic hormon es via the portal system. However, our recent studies have demonstrate d the presence of a substantial amount of substance P (SP)-, calcitoni n gene-related peptide (CGRP)- and galanin (GAL)- immunoreactive (ir) nerve fibers with numerous varicosities in the anterior pituitaries of the Macaca mulatta monkey. The present study investigated the relatio nship of the GAL-ir nerve fibers to the glandular cells. The M. mulatt a monkeys were used and the sections of the anterior pituitary were do uble immunostained. GAL-ir nerve fibers and/or varicosities were found in proximity to contact directly with corticotropes, somatotropes, la ctotropes, gonadotropes and thyrotropes without any exception. These f indings indicate that a direct neural factor may be involved in the re gulation of adenohypophyseal secretion. (C) 1998 Elsevier Science B.V.