Kim Dokyung, Lee Moon-Hwan, Kim Sung Kyo
Department of Conservative Dentistry, Kyungpook National University School of Dentistry, Daegu, Korea.
Restor Dent Endod. 2016 Aug;41(3):202-9. doi: 10.5395/rde.2016.41.3.202. Epub 2016 Jul 29.
The purpose of this study was to investigate the involvement of TRPA1 in the cinnamaldehyde-induced pulpal blood flow (PBF) change in the feline dental pulp.
Mandibles of eight cats were immobilized and PBF was monitored with a laser Doppler flowmetry at the mandibular canine tooth. To evaluate the effect of cinnamaldehyde on PBF, cinnamaldehyde was injected into the pulp through the lingual artery at a constant rate for 60 seconds. As a control, a mixture of 70% ethanol and 30% dimethyl sulfoxide (DMSO, vehicle) was used. To evaluate the involvement of transient receptor potential ankyrin 1 (TRPA1) in PBF change, AP18, a specific TRPA1 antagonist, was applied into the pulp through the Class V dentinal cavity followed by cinnamaldehyde-administration 3 minutes later. The paired variables of experimental data were statistically analyzed using paired t-test. A p value of less than 0.05 was considered as statistically significant.
Administration of cinnamaldehyde (0.5 mg/kg, intra-arterial [i.a.]) induced significant increases in PBF (p < 0.05). While administration of a TRPA1 antagonist, AP18 (2.5 - 3.0 mM, into the dentinal cavity [i.c.]) caused insignificant change of PBF (p > 0.05), administration of cinnamaldehyde (0.5 mg/kg, i.a.) following the application of AP18 (2.5 - 3.0 mM, i.c.) resulted in an attenuation of PBF increase from the control level (p < 0.05). As a result, a TRPA1 antagonist, AP18 effectively inhibited the vasodilative effect of cinnamaldehyde (p < 0.05).
The result of the present study provided a functional evidence that TRPA1 is involved in the mechanism of cinnamaldehyde-induced vasodilation in the feline dental pulp.
本研究旨在探讨瞬时受体电位锚蛋白1（TRPA1）在肉桂醛诱导的猫牙髓牙髓血流（PBF）变化中的作用。
固定八只猫的下颌骨，在下颌犬齿处用激光多普勒血流仪监测PBF。为评估肉桂醛对PBF的影响，以恒定速率通过舌动脉将肉桂醛注入牙髓60秒。作为对照，使用70%乙醇和30%二甲基亚砜（DMSO，溶媒）的混合物。为评估瞬时受体电位锚蛋白1（TRPA1）在PBF变化中的作用，通过V类牙本质小管将特异性TRPA1拮抗剂AP18注入牙髓，3分钟后给予肉桂醛。实验数据的配对变量采用配对t检验进行统计学分析。p值小于0.05被认为具有统计学意义。
给予肉桂醛（0.5mg/kg，动脉内[i.a.]）可使PBF显著增加（p<0.05）。虽然给予TRPA1拮抗剂AP18（2.5 - 3.0mM，牙本质小管内[i.c.]）导致PBF无显著变化（p>0.05），但在应用AP18（2.5 - 3.0mM，i.c.）后给予肉桂醛（0.5mg/kg，i.a.）导致PBF从对照水平的增加减弱（p<0.05）。结果，TRPA1拮抗剂AP18有效抑制了肉桂醛的血管舒张作用（p<0.05）。
本研究结果提供了功能性证据，表明TRPA1参与了肉桂醛诱导的猫牙髓血管舒张机制。
