TITLE:
Serotonin Influences the Endogenous Opiate Peptides in the Rat Spinal Cord to Participates in Pain Modulation
AUTHORS:
Yan-Juan Pan, Zhi-Kui Yin, Jun Yang, Ying Zhao, Da-Xin Wang
KEYWORDS:
Serotonin; Endogenous Opiate Peptide; Spinal Cord; Antinociception
JOURNAL NAME:
Open Journal of Anesthesiology,
Vol.2 No.2,
April
19,
2012
ABSTRACT: Spinal cord is a necessary pathway that transfers the body nociceptive inputs to the brain. Endogenous opiate peptides have been proven to participate in the nociceptive process at spinal level. It has reported that serotonin (5-HT, 5-hydroxytryptamine) in spinal cord plays a role in pan modulation, which can be blocked by opiate receptor antagonists. The present study was designed to investigate the interaction between 5-HT and endogenous opiate peptides at rat spinal level effecting on pain modulation. The results showed that 1) pain stimulation increased not only leucine-enkephalin (L-Ek), β-endorphin (β-Ep) and dynorphin A1-13 (DynA1-13) concentrations but also 5-HT and 5-hydorxyindoleace acid (5-HIAA, the 5-HT main metabolic product) concentrations in spinal cord significantly; 2) 5-HT could increase L-Ek, β-Ep and DynA1-13 concentrations in spinal cord in a dose-dependent manner, whereas cypotolamine (a 5-HT receptor antagonist) decreased L-Ek, β-Ep and DynA1-13 concentrations in spinal cord. The data suggested that 5-HT antinociceptive role might be involved in the endogenous opiate peptide system through 5-HT receptors at spinal level.