| Background and object:Corticotropin-releasing hormone (CRH) is a peptide involved in the activation of the hypothalamic-pituitary adrenal axis. It is released from the hypothalamus and stimulates the anterior-pituitary gland to release adrenocorticotropic hormone, which then activates the adrenal gland to release corticosteroids. Recently, CRH has been recognized for its ability to produce analgesia by all routes of administration attempted, including local, systemic, and central routes, highlighting the fact that CRH can affect pain processing at all levels of the euraxis. Opiods are usually administrated for analgesia in clinic treatment, but their side effects such as respirtory depression tolerance and addiction are worried. In order to provide exprimental basis for appropriate combination of analgesic drugs.The purpose of the present study is to observe the effect of formalin-induced inflammatory pain on the expression of CRH in the dorsal horn of spinal cord, to approach the antinociceptive efficacy of pre-emptive intrathecal administration of CRH and its possible mechanism in the formalin test through immunohistochemical and behavioral study.Methods:Experiment 1: The effect of formalin-induced inflammatory pain on the expression of CRH in the dorsal horn of spinal cord. Thirty SD rats were randomly divided into 5 groups with six in each group: control, 2h, 12h, 24h, 48h group. The inflammatory pain and hyperalgesia were induced by subcutaneous injection of 5% formalin solution (0.lml) into the plantar region of the right hindpaw. Rats were deeply anesthetized and sacrificed at the relevant time after formalin test. The changes of expression and concentrations of CRH in the spinal cord in rats were detected by immunohistochemistry.Experiment 2: The antinociceptive efficacy of pre-emptive intrathecal administration of CRH during formalin-induced inflammatory pain. SD rats were randomly divided into 7...
|
PDF Full Text Request