Novel secreted peptides represent an important field of research because delineation of their
function affords new insights into the pathophysiological processes causing disease, and
provides opportunities for the development of pharmacological therapies. Augurin is a recently
identified secreted peptide of unknown function expressed in the central nervous system (CNS),
pituitary, and several endocrine tissues. Because of its expression pattern I hypothesised that
augurin may be involved in the neuroendocrine system. I therefore investigated the effects of
central injection of augurin on the hypothalamo-pituitary axes and food intake in male Wistar
rats.
Intracerebroventricular (ICV) or intraparaventricular nucleus (iPVN) injection of augurin
increased plasma adrenocorticotrophic hormone (ACTH) and corticosterone levels compared
with vehicle-injected controls. Augurin also increased the release of corticotrophin releasing
hormone (CRH) from hypothalamic explants, and pre-treatment with a CRH receptor antagonist
in vivo prevented the rise in ACTH and corticosterone caused by ICV augurin, suggesting
activation the hypothalamo-pituitary-adrenal (HPA) axis via by the release of CRH from
neurons in the PVN. In addition to stimulating the HPA axis, iPVN injection of augurin at the
start of either the light or dark phase caused a robust increase in food intake.
To assess whether augurin might have a physiological role in the regulation of the HPA axis or
food intake, I investigated its endogenous distribution in the rat CNS using
immunohistochemistry and in situ hybridisation histochemistry. Augurin positive neurons were
present in several regions of the CNS including the hypothalamus and the dorsal vagal complex
of the brainstem, a distribution consistent with a possible role in neuroendocrine function.
Augurin is therefore anatomically positioned to play a role in the hypothalamic regulation of the
HPA axis and food intake.
While the data presented suggest a novel role for augurin, these are preliminary studies.
Currently, little is known about the physiology of the augurin system. Further characterisation
of the neuroanatomy, identification of receptors, and the development of receptor agonists and
antagonists would provide further data on the physiological role of augurin, and on the potential
therapeutic benefits of manipulating the augurin system
