Endocrine Abstracts

Particulate guanylyl cyclases are expressed in all endocrine organs and serve as specific receptors of the natriuretic peptides ANP, BNP and CNP. Guanylyl cyclase-B (GC-B/Npr2) receptors specifically mediate the biological effects of CNP in its target tissues. Targeted disruption of either CNP or GC-B results in pituitary growth hormone deficiency and dwarfism as a result of achondroplasia. Despite this, molecular regulation of GC-B expression is poorly elucidated. Therefore, ...

Introduction: Patients with aryl hydrocarbon receptor-interacting protein (AIP) gene mutations are predisposed to large, invasive, GH- or PRL-secreting pituitary tumours, occurring at a younger age and poorly responsive to treatment. The zebrafish (ZF) model provides anatomical and functional similarities to human neuroendocrine system.Methods: AIP knock down (KD) ZF embryos were generated using antisense morpholino oligonucleotides injected at one-cell ...

C-type natriuretic peptide (CNP), the predominant natriuretic peptide in the pituitary, is associated with neuroendocrine development and function. Our previous studies show that genes encoding CNP (nppc2, cnp3, nppc4, and nppcl) are expressed during pituitary development in humans and zebrafish (Danio rerio), however a precise role for CNP in the pituitary has yet to be elucidated. Using the versatile zebrafish, we explored in ...

Follistatin-like 3 (FSTL3) is an endogenous glycoprotein inhibitor of transforming growth factor-β (TGFβ) ligands such as activin. TGFβ ligands are integral to key cellular processes such as proliferation, development and differentiation, including angiogenesis. It is not clear, however, how FSTL3 and activin action affect tissue and organ functions in health and disease. We have identified a group of activin-responsive genes that have an expression pattern clos...

C-type natriuretic peptide (CNP) is the ancestral and most highly conserved member of the mammalian natriuretic peptide family. Although broadly expressed throughout the periphery (bone, gonads, kidneys), CNP is the major natriuretic peptide of the brain and CNS and is suspected to influence neuroendocrine function. Our recent studies using fetal human pituitary samples has shown that the gene encoding CNP, NPPC, is expressed early on in pituitary development but a co...

C-type natriuretic peptide (CNP) has recently been implicated as a key meiotic arrest factor in oocytes, and mechanistic studies suggest that the transcriptional regulation of the CNP gene (Nppc) and of its receptor, GC-B (Npr2) is sensitive to gonadotrophin-dependent cAMP accumulation. We have shown CNP to be a major regulator of gonadotrophs in the pituitary, but have yet to establish how either Nppc or Npr2 are transcriptionally controlled locally. In the current study, the...

The cardiovascular properties of the natriuretic peptide family of hormones are well-characterised, and provide valuable prognostic indicators in the treatment of heart failure in humans and companion animals. Of the three main mammalian natriuretic peptides, C-type natriuretic peptide (CNP) remains the most enigmatic, even though CNP represents the ancestral natriuretic peptide from which Atrial- (ANP) and B-type (BNP) natriuretic peptides evolved through gene duplication. We...

The mammalian natriuretic peptide family consists of three members, Atrial-, B-type, and C-type natriuretic peptides (ANP, BNP, and CNP respectively), and exert their effects on blood pressure, sodium homeostasis, growth and reproduction, via their selective guanylyl cyclase receptors, GC-A or GC-B. Previous attempts to map spatial expression profiling have generated conflicting results, due predominantly to the range of techniques employed, and the relative paucity of tools t...

Gonadotrophs in rats, mice and humans, express an intact natriuretic peptide system, in which C-type natriuretic peptide (CNP) is the predominant member. Despite showing an interaction between CNP and GnRH at the level of cGMP and Ca2+ signalling, the role of CNP in gonadotroph biology is poorly understood. In this study, we utilise a novel multiplex qRT-PCR assay, examining simultaneous expression of natriuretic peptide genes along with genes for gonadotroph transc...

Atrazine (ATR) is a widely used herbicide, with known effects as an endocrine disrupting chemical. Several studies have implicated ATR in causing disorders of sex development in reptiles, and chronic exposure can cause an increase incidence of intersex in fish, suggesting that the hypothalamo-pituitary–gonadal axis is a major site of ATR action. In this study, we investigated whether acute exposure (hours to days) to ATR could cause abnormalities in the development of Zeb...