Expression Of Galanin In Trigeminal Ganglion Of Rat During The Experimental Tooth Movement

During the treatment, the amount of pain occurring could make the patient fear Orthodontic treatment. According to the survey, besides being able to tolerate pain in Orthodontics, it's also the main reason for stopping treatment. Currently, researchers monitor the effects of neuropeptide in order to investigate the mechanism of pain and ways of relieving it.When the mechanical force impacted on the teeth, it can cause teeth, alveolar bone and periodontal tissues appeared a series of changes. So that the teeth move in the alveolar bone. Periodontal ligament was pulled in one side, the other side being squeezed. Periodontal gap of the Pressured side narrowed, and the vascular was pressed, with blood flow reduced. The changes of blood flow in periodontal tissue and release of inflammatory mediators were important reasons for pain. Inflammatory mediators such as substance P, histamine, enkephalin, dopamine, serotonin, glycine, prostaglandin, interleukin, and a variety of cytokines were produced during orthodontic treatment. Earlier studies suggest that inflammatory mediators were all blood-borne, and later study found that when mechanical force impacted on the teeth, the neuron will respond to this stimulus and release a variety of neuropeptides, kown as neurogenic inflammation. Pain-related neuropeptides including SP, CGRP, neuropeptide Y, nerve growth factor, vasoactive intestinal peptide and so on were produced during orthodontic treatment. Studies have shown that these neuropeptides played an important role in the regulation on the alveolar bone alteration and pain. Researchers discovered the GAL is a type of endogenous analgesic. It is widely distributed in the central and peripheral nervous systems and plays an important role in physiological and pathological processes. However, the mechanism of analgesic effect of GAL is unclear about the variation and effects of GAL at home and abroad now .At present, studies show that GAL distributes in the peripheral and central nervous system and plays a complex role in pian transmission and regulation, mainly an inhibitory effect. It is an endogenous analgesic substance. But the mechanism induced analgesia of GAL is not clear. Research has shown that GAL might affect other neurotransmitters such as Galanin and calcitonin gene-related peptide (CGRP), P substance and enkephalin during orthodontic treatment. Studies on GAL at home and abroad in the central nervous system focused on its role and mechanism of the analgesic. GAL in the changes of orthodontic pain and its function has not been reported.ObjectiveExplore the variation of the GAL during the orthodontic movement and compare the variation in periodontal tissue. Create the theoretical foundation to study of orthodontic treatment of pain treatment.Method35 male rats were selected and randomly divided into the experiment group (30rats) and the control group (5rats). The left of experiment group is the experiment, and the other is comparison.Rats were anesthetized by intramuscular injection with sumianxin. Extract rat trigeminal ganglion from the head of rat. ResultAfter 6 hours treated by 50g force, GAL-immunoreactive ganglion cells in experimental trigeminal ganglia compared with the control side has no statistically significant difference (P> 0.05); After 12 hours and 1days treated by 50g force, the area of GAL-immunoreactive ganglion cells in experimental trigeminal ganglia increased in a minor extent. And the difference between the experimental side and control side has no statistically significant difference(P>0.05). After 3 days group, 5 days group treated by 50g force, GAL-immunoreactive ganglion cells in experimental trigeminal ganglia increased. And there are a great significance between the experiment and control (P<0.01). Peak appeared in 5 days. After 7 days, GAL-immunoreactive ganglion cells in experimental trigeminal ganglia began to decrease. Compared with 5 days group and 3 days group, GAL-immunoreactive ganglion cells in experimental trigeminal ganglia in 7 days decreased , but higher than the 6 hours group and 12 hours group, 1day group.Conclusion1). There is a small quantity of GAL in normal rat TG cell.2). Orthodontic movement in rats can lead to incresed expression of GAL in the TG cell.3). The expression of GAL in experimental group during the experiment showed a significant law. The expression of GAL in experimental group begin to increase after 3 days, and it reaches peak after 5 days. The expression of GAL in experimental group decreased after 7 days.4). This trend conformed to the trend of enmergence and relieve of pain in orthodontic treatment and it suggested that GAL as an endogenous analgesic substance associated with the tooth and periodontal pain which caused by orthodontic tooth movement.