CGRP对辣椒素致痛大鼠热刺激缩足反射潜伏期的影响

目的：通过测大鼠的PWTL，探讨CGRP对辣椒素致痛大鼠热痛觉过敏的影响。方法：雌性SD大鼠48只，体重200—220g，随机分为6组，每组都为8只，A组：正常对照组；B组：生理盐水组；C组：大腿背侧坐骨神经干周围注射辣椒素组；D组：腹腔注射生理盐水＋大腿背侧坐骨神经干周围注射辣椒素组；E组：腹腔注射CGRP＋大腿背侧坐骨神经干周围注射辣椒素组；F组：腹腔注射CGRP8-37大腿背侧坐骨神经千周围注射辣椒素组。分别在注射前及注射后10、20、30、40、50、60min进行热板实验。结果：辣椒素组，大鼠的PWTL比实验前明显缩短（P〈0．05），给予CGRP干预后，大鼠的PWTL与实验前和单独注射辣椒素组相比明显缩短（P〈0．05），给予CGRP受体竞争性拮抗剂CGRP8-37干预后，发现大鼠的PWTL较GGRP干预组明显延长，差异有统计学意义（P〈0．05）。结论：CGRP能促进辣椒素致痛大鼠痛阈降低、痛觉过敏，而CGRP8-37能对抗这种伤害效应。

The effect of CGRP on paw withdraw thermal latency on capsaicin-induced pain rats

Objective： Through the measurement of thermally stimulated rat withdrawal reflex latency （ paw withdraw thermal latency, PWTL） , to explore the impact of calcitonin gene-related peptide （CGRP） on capsaicin-indueed pain in rats. Methods ： forty eight female SD rats weighing 200 - 220g were randomly divided into six groups, each group has eight animals, Group A ： normal control group ; Group B ： saline group ; Group C ： dorsal thigh sciatic nerve injection of capsaicin group luck around ; Group D ： intraperitoneal injection saline ＋ thigh dorsal do around the sciatic nerve injection of capsaicin group; Group E： intraperitoneal injection of CGRP ＋ thigh dorsal do around the sciatic nerve injection of capsaicin group; Group F： intraperitoneal injection CGRP8-37 ＋ thigh dorsal do around the sciatic nerve injection of capsaicin group. Separately in injection before and after injection 10,20,30,40,50,60 miu for hot-plate test. Results：The eapsaicin group PWTL rats was significantly shorter than before the experiment （ P 〈 0.05 ）. CGRP given after the intervention and PWTL
rats before the experiment and the capsaicin group was significantly shorter （ P 〈 0.05 ）. Given the competitive CGRP receptor antagonist CGRP8-37 after the intervention and found that PWTL rats was longer than the CGRP group（ P 〈 0.05 ）. Conclusion：CGRP can promote capsaicin-induced pain in rats, reduce pain threshold and improving hyperalgesia, and CGRP8-37 can combat the effects of the injury.