title: Spinal vasopressin alleviates formalin-induced nociception by enhancing GABAA receptor function in mice.
abstract: Arginine vasopressin (AVP) plays a regulatory role in nociception. Intrathecal administration of AVP displays an antinociceptive effect. However, little is understood about the mechanism underlying spinal AVP analgesia. Here, we have found that spinal AVP dose dependently reduced the second, but not first, phase of formalin-induced spontaneous nociception in mice. The AVP analgesia was completely blocked by intrathecal injected SR 49059, a vasopressin-1A (V1A) receptor antagonist. However, spinal AVP failed to exert its antinociceptive effect on the second phase formalin-induced spontaneous nociception in V1A receptor knock-out (V1A-/-) mice. The AVP analgesia was also reversed by bicuculline, a GABAA receptor antagonist. Moreover, AVP potentiated GABA-activated currents in dorsal root ganglion neurons from wild-type littermates, but not from V1A-/- mice. Our results may reveal a novel spinal mechanism of AVP analgesia by enhancing the GABAA receptor function in the spinal cord through V1A receptors.
authors.affiliation: Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China; Department of Anatomy and Histology & Embryology, College of Basic Medicine, Wenzou Medical University, Wenzou 32500, Zhejiang, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Peng
authors.affiliation: Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China.
authors.forename: Zu-Wei
authors.initials: ZW
authors.lastname: Qu
authors.affiliation: Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China.
authors.forename: Chun-Yu
authors.initials: CY
authors.lastname: Qiu
authors.affiliation: Department of Anatomy and Histology & Embryology, College of Basic Medicine, Wenzou Medical University, Wenzou 32500, Zhejiang, PR China. Electronic address: liaomin70@126.com.
authors.forename: Min
authors.initials: M
authors.lastname: Liao
authors.affiliation: Institute of Ion Channels, Department of Pharmacology, Hubei University of Science and Technology, 88 Xianning Road, Xianning 437100, Hubei, PR China. Electronic address: wangping_hu@163.com.
authors.forename: Wang-Ping
authors.initials: WP
authors.lastname: Hu
mesh_terms: D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists / Q000494:pharmacology; D001127:Arginine Vasopressin / Q000378:metabolism* / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000503:physiopathology; D007278:Injections, Spinal; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000502:physiology; D059225:Nociception / Q000187:drug effects*; D059226:Nociceptive Pain / Q000378:metabolism / Q000503:physiopathology / Q000523:psychology*; D010147:Pain Measurement; D011963:Receptors, GABA-A / Q000378:metabolism*; D017483:Receptors, Vasopressin / Q000235:genetics / Q000378:metabolism*; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000700:Analgesics; D065092:Antidiuretic Hormone Receptor Antagonists; D058787:GABA-A Receptor Antagonists; D011963:Receptors, GABA-A; D017483:Receptors, Vasopressin; D001127:Arginine Vasopressin
keywords: Arginine vasopressin; Formalin test; GABA(A) receptor; Knock-out; Pain; Vasopressin-1A receptor