摘要
BACKGROUND： Previous morphological studies have demonstrated that group Ⅲ metabotropic glutamate receptors （mGluRs） are commonly found in nociceptive pathways, particularly in the terminals of primary afferent fibers in the spinal dorsal horn. OBJECTIVE： To investigate the role of group Ⅲ mGluRs in a rat model of spinal nociception by intrathecal administration of a selective agonist, L-Serine-O-phosphate （L-SOP）. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment. The study was performed at the Department of Physiology and Neurobiology, Shanxi Medical University, between March 2007 and May 2008. MATERIALS： L-SOP of group Ⅲ mGluRs （Tocris Cookson Ltd, UK）, formalin （Sigma, USA）, rabbit anti-c-Fos polyclonal antibody and biotin-labeled goat anti-rabbit IgG （Cell Signaling Technology, USA） were used in this study. METHODS： A total of 26 healthy Wistar rats, aged 1 month and weighing 100-120 g, were subjected to intrathecal catheter implantation. After 5-8 days, 10 rats were selected according to experimental requirements. L-SOP 250 nmol in 10 μL, or the equivalent volume of normal saline, was administered by intrathecal injection into the L3-5 region of the spinal cord in the experimental and control groups, respectively. After 15 minutes, formalin （5%, 50 μL） was subcutaneously injected into the plantar of the left hindpaw of each rat to establish formalin-induced pain models. MAIN OUTCOME MEASURES： Nociceptive behavioral responses and immunohistochemical examination of Fos expression. RESULTS： Intrathecal injection of L-SOP significantly attenuated the second phase nociceptive response compared with the control group （P 〈 0.05）, and Fos expression in the spinal dorsal horn was significantly decreased along with the number of Fos-like immunoreactive neurons （P 〈 0.05）. CONCLUSION： Group Ⅲ mGluRs are involved in the modulation of nociceptive signals, and their activation suppresses the transmission of nociceptive signals.
BACKGROUND： Previous morphological studies have demonstrated that group Ⅲ metabotropic glutamate receptors （mGluRs） are commonly found in nociceptive pathways, particularly in the terminals of primary afferent fibers in the spinal dorsal horn. OBJECTIVE： To investigate the role of group Ⅲ mGluRs in a rat model of spinal nociception by intrathecal administration of a selective agonist, L-Serine-O-phosphate （L-SOP）. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment. The study was performed at the Department of Physiology and Neurobiology, Shanxi Medical University, between March 2007 and May 2008. MATERIALS： L-SOP of group Ⅲ mGluRs （Tocris Cookson Ltd, UK）, formalin （Sigma, USA）, rabbit anti-c-Fos polyclonal antibody and biotin-labeled goat anti-rabbit IgG （Cell Signaling Technology, USA） were used in this study. METHODS： A total of 26 healthy Wistar rats, aged 1 month and weighing 100-120 g, were subjected to intrathecal catheter implantation. After 5-8 days, 10 rats were selected according to experimental requirements. L-SOP 250 nmol in 10 μL, or the equivalent volume of normal saline, was administered by intrathecal injection into the L3-5 region of the spinal cord in the experimental and control groups, respectively. After 15 minutes, formalin （5%, 50 μL） was subcutaneously injected into the plantar of the left hindpaw of each rat to establish formalin-induced pain models. MAIN OUTCOME MEASURES： Nociceptive behavioral responses and immunohistochemical examination of Fos expression. RESULTS： Intrathecal injection of L-SOP significantly attenuated the second phase nociceptive response compared with the control group （P 〈 0.05）, and Fos expression in the spinal dorsal horn was significantly decreased along with the number of Fos-like immunoreactive neurons （P 〈 0.05）. CONCLUSION： Group Ⅲ mGluRs are involved in the modulation of nociceptive signals, and their activation suppresses the transmission of nociceptive signals.
基金
the Natural Science Foundation for Young Scientists of Shanxi Province,No.2006021040
