| Objective: To explore the mechanism of endogenous corticotropin-releasing hormone (CRH) involvement in acupuncture analgesia and neuro-endocrine-immunity (NEI) regulation, by observing the influence of intrathecally (icv) administered anti-CRH serum(ACRHS) on the analgesic and NEI regulatory effects of electro-acupuncture (EA) at EX-B2 in CFA-induced arthritis inflammatory pain mode(lAA)rats; to preliminarily probe the cellular signal transduction mechanism of endogenous CRH in its involvement in acupuncture analgesia, by studying the expression changes of inhibitory GTP-binding protein (Gi) in hypothalamus after EA and intrathecal ACRHS injection in AA rats; to investigate the relationship between endogenous CRH and central 5-hydroxytryptamine (5-HT), by observing the influences of administrated icv anti-CRH serum and anti-5-HT serum on the pain threshold of AA rats as well as on the analgesic roles of EA in these rats.Methods: AA rats were used as the subjects of the study. By using methods of pain behavior observation, foot cubage measurement, radioimmunoassay and MTT, we observed the roles of EA at EX-B2 and intrathecal ACRHS injection on the pain threshold, foot cubage, the contents of 5-HT in hypothalamus,the contents of?-endorphin in hypothalamus and spinal cord, the level of IL-6 and TNF-?in blood serum of AA rats. Both the expression of CRH and Gi in hypothalamus following the above-mentioned treatments were also observed with methods of immunohistochemistry and western blot. Moreover, we observed the influences of administrated icv anti-CRH serum and anti-5-HT serum on the pain threshold of AA rats as well as on the EA analgesic effects on these rats.Results: By using electro-acupuncture at EX-B2, the pain threshold of AA rats was heightened, the foot cubage as well as foot swelling rate were reduced, the contents of?-EP in hypothalamus and spinal cord increased and the IL-6 level in blood serum decreased. After the intrathecal injection of anti-CRH serum, however, the pain threshold of AA rats was lowered, EA analgesic effects weakened, the contents of 5-HT and?-EP in hypothalamus and the contents of?-EP in spinal cord decreased, while the level of IL-6 and TNF-?in blood serum increased. The intrathecal injection of ACRHS brought down the expressions of CRH, while EA increased its expressions. Both EA and the ACRHS intrathecal injection can modulate the expression of Gi in the hypothalamus of AA rats. Endogenous CRH and central 5-HT are interrelated in EA analgesia.Conclusion: Endogenous CRH may be a pivotal regulative point for acupuncture analgesia and regulation of NEI, and its role may be related to the G-protein mediated signal transduction pathway. |
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