Physiological Roles of GPR10 and PrRP Signaling

Abstract

Prolactin-releasing peptide (PrRP) was first isolated from bovine hypothalamus, and was found to act as an endogenous ligand at the G-protein-coupled receptor 10 (GPR10 or hGR3). Although originally named as it can affect the secretion of prolactin from anterior pituitary cells, the potential functions for this peptide have been greatly expanded over the past decade. Anatomical, pharmacological, and physiological studies indicate that PrRP, signaling via the GPR10 receptor, may have a wide range of roles in neuroendocrinology; such as in energy homeostasis, stress responses, cardiovascular regulation, and circadian function. This review will provide the current knowledge of the PrRP and GPR10 signaling system, its putative functions, implications for therapy, and future perspectives.

Keywords: GPR10; PrRP; dorsomedial hypothalamic nucleus; energy intake; energy metabolism; nucleus tractus solitarius; stress.

Figure 1

Schematic drawings showing the neuronal distribution of PrRP and GPR10 receptor in the Paxions and Watson rat brain atlas (Paxinos and Watson, ; Sun et al., 2005). Blue areas represent PrRP-immunopositive nerve fibers; black checkers represent PrRP cells bodies; green areas represent GPR10 expression; and red areas represent overlap of PrRP and GPR10 expression. AP, area postrema; BL, basolateral amygdaloid nucleus; BNST, bed nucleus of the stria terminalis; Ce, central amygdaloid nucleus; DMN, dorsomedial hypothalamic nucleus; LH, lateral hypothalamic area; MCPO, magnocellular preoptic nucleus; MD, mediodorsal thalamic nucleus; MPO, medial preoptic nucleus; ox, optic chiasm; PVN, paraventricular hypothalamic nucleus; Pe, periventricular hypothalamic nucleus; PT, paratenial thalamic nucleus; Rt, reticular thalamic nucleus; SM, nucleus of the stria medullaris; SO, supraoptic hypothalamic nucleus; NTS, nucleus of the tractus solitarius; SpVe, spinal vestibular nucleus; VLH, ventrolateral hypothalamic nucleus.