Neuropeptides in anterior pituitary development

Abstract

Recent studies using biotechnological methods have achieved significant advances in our knowledge of molecular mechanisms underlying pituitary gland development and the differentiation of pituitary cytotypes. A large number of neuropeptides have been reported in the adult pituitary gland as well as in the central and peripheral nervous system. The early presence of neuropeptides during pituitary development is reviewed here. Neuromedin U (NmU), galanin and the polypeptide 7B2 have been localised to different endocrine cells of the gland. Their expression seems to be manifold even though it is temporally and spatially regulated. There is now firm immunocytochemical evidence that neuropeptides are present during morphogenesis of the pituitary and can be present simultaneously with all pituitary hormones.

Neuromedins U and S involvement in the regulation of the hypothalamo–pituitary–adrenal axis

“…Electron microscopy studies revealed NMU-like immunoreactivity in some thyrotropes and most corticotropes of the rat pituitary gland. NMU is colocalized with galanin and ACTH in the same secretory granules (Cimini et al, 1993; for review see Malendowicz, 1998; Cimini, 2003). …”

“…In developing rat NMU-immunopositive cells appear in anterior pituitary at day E15 (Cimini, 2003). Their number increases at day E20 and then decreases.…”

Annotation and analysis of expressed sequence tags (ESTs) from Chinese sturgeon (Acipenser sinensis) pituitary cDNA library

“…Protein 7B2 is produced as an intracellular precursor of 25-29 kDa, which is converted into a secreted form of 18-21 kDa (Mbikay et al, 2001). The function of protein 7B2 has been related to cell secretion regulation and signal transduction (Cimini, 2003). CPH, also known as enkephalin convertase, is involved in the biosynthesis of bioactive peptides, which are probably involved in the removal of residual COOH-terminal arginine or lysine residues from peptide hormone precursors during their processing in secretory granules (Dalle Ore et al, 1999).…”

“…A large number of important biomolecules in the pituitary, such as neurotransmitters and neuropeptides including growth and differentiation factors, are involved in cell regulation (Cimini, 2003). Several neuropeptides are found in the different endocrine cells of pituitary: substance P, neuromedin B, neuropeptide Y, neuromedin U, galanin and the polypeptide 7B2 (Cimini, 2003;Mbikay et al, 2001).…”

“…Several neuropeptides are found in the different endocrine cells of pituitary: substance P, neuromedin B, neuropeptide Y, neuromedin U, galanin and the polypeptide 7B2 (Cimini, 2003;Mbikay et al, 2001). Many proteolytic enzymes specific to the pituitary have important functions in regulating the synthesis of hormones and neuropeptides (Orlowski, 1983).…”