| Summary: | 碩士 === 國立中央大學 === 生命科學研究所 === 99 === Serotonin (5-hydroxtryptamine [5-HT]) is one of the inflammatory mediators present in central and peripheral nervous system. After injury or inflammation, 5-HT is released from platelets and mast cells to peripheral nervous system, causing pain and hyperalgesia. 5-HT receptors include seven subtypes (5HT1-7). However, it remains unclear which subtype of 5-HT receptors is involved in 5-HT-induced pain and hyperalgesia. In this study, we have investigated the roles of 5-HT2B receptors in 5-HT-induced pain and hyperalgesia. We have found that injection of 5-HT or 5-HT2 agonist ?-m-5HT produces significant hyperalgesia to mechanical stimuli. The mechanical hyperalgesia induced by 5-HT injection is inhibited by 5-HT2B/2C antagonist SB206553, but not 5-HT2A antagonist Ketanserin, suggesting that 5-HT2B or 5-HT2C receptors are involved in 5-HT-induced mechanical hyperalgesia. Given that 5-HT2C receptor is not present in not present in DRG, it could be 5-HT2B receptor involved in 5-HT-induced mechanical hyperalgesia. To further understand the mechanism of 5HT2B-mediated mechanical hyperalgesia, we co-transfect 5-HT2B and ion channels that are related to hyperalgesia (such as ASICs or TRPV1) to human embryo kidney 293T cells (HEK293T), and examine whether 5-HT2B receptor regulates these ion channels by calcium image.
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