title: The Gastrin-Releasing Peptide Receptor (GRPR) in the Spinal Cord as a Novel Pharmacological Target.
abstract: Gastrin-releasing peptide (GRP) is a mammalian neuropeptide that acts through the G protein-coupled receptor, GRP receptor (GRPR). Increasing evidence indicates that GRPR-mediated signaling in the central nervous system plays an important role in many physiological processes in mammals. Additionally, we have recently reported that the GRP system within the lumbosacral spinal cord not only controls erection but also triggers ejaculation in male rats. This system of GRP neurons is sexually dimorphic, being prominent in male rats but vestigial or absent in females. It is suggested that the sexually dimorphic GRP/GRPR system in the lumbosacral spinal cord plays a critical role in the regulation of male sexual function. In parallel, it has been reported that the somatosensory GRP/GRPR system in the spinal cord contributes to the regulation of itch specific transmission independently of the pain transmission. Interestingly, these two distinct functions in the same spinal region are both regulated by the neuropeptide, GRP. In this report, we review findings on recently identified GRP/GRPR systems in the spinal cord. These GRP/GRPR systems in the spinal cord provide new insights into pharmacological treatments for psychogenic erectile dysfunction as well as for chronic pruritus.
authors.affiliation: Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Takanami
authors.affiliation: Ushimado Marine Institute (UMI), Graduate School of Natural Science and Technology, Okayama University, Ushimado, Setouchi, Okayama 701-4303, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Sakamoto
keywords: Chronic pruritus; erectile dysfunction; gastrin-releasing peptide; gastrin-releasing peptide receptor; sexual function; somatosensory; spinal cord.