||Tranexamic acid evokes pain by modulating neuronal excitability in the spinal dorsal horn.
Ohashi, Nobuko大橋, 宣子
学位の種類: 博士（医学）. 報告番号: 甲第4128号. 学位記番号: 新大院博（医）甲第695号. 学位授与年月日: 平成28年3月23日
Scientific Reports. 2015, 5, 13458.
Tranexamic acid (TXA) is an antifibrinolytic agent widely used to reduce blood loss during surgery. However, a serious adverse effect of TXA is seizure due to inhibition of γ-aminobutyric acid (GABA) and glycine receptors in cortical neurons. These receptors are also present in the spinal cord, and antagonism of these receptors in spinal dorsal horn neurons produces pain-related phenomena, such as allodynia and hyperalgesia, in experimental animals. Moreover, some patients who are injected intrathecally with TXA develop severe back pain. However, the effect of TXA on spinal dorsal horn neurons remain poorly understood. Here, we investigated the effects of TXA by using behavioral measures in rats and found that TXA produces behaviors indicative of spontaneous pain and mechanical allodynia. We then performed whole-cell patch-clamp experiments that showed that TXA inhibits GABA_A and glycine receptors in spinal dorsal horn neurons. Finally, we also showed that TXA facilitates activation of the extracellular signal-regulated kinase in the spinal cord. These results indicated that TXA produces pain by inhibiting GABA_A and glycine receptors in the spinal dorsal horn.