Li N, Lundeberg T, Yu L C
Department of Physiology, College of Life Science, and National Laboratory of Biomembrane and Membrane Biotechnology, Peking University, 100871, Beijing, People's Republic of China.
Brain Res. 2001 May 18;901(1-2):161-6. doi: 10.1016/s0006-8993(01)02341-1.
The present study was performed to investigate the role of calcitonin gene-related peptide (CGRP) and its antagonist CGRP8-37 on nociception in the nucleus accumbens of rats. Hindpaw withdrawal latencies (HWLs) to noxious stimulation induced by hot plate and Randall Selitto tests were measured. The HWL to both thermal and mechanical stimulation increased significantly after intra-nucleus accumbens administration of 0.5 or 1 nmol of CGRP, but not 0.1 nmol, indicating that CGRP plays an anti-nociceptive effect in the nucleus accumbens of rats. The anti-nociceptive effect induced by intra-nucleus accumbens administration of 1 nmol of CGRP was blocked significantly by following intra-nucleus accumbens administration of 1 nmol of CGRP8-37, a selective antagonist of CGRP1 receptor. Furthermore, the HWLs to both thermal and mechanical stimulation decreased significantly after intra-nucleus accumbens administration of 0.02, 0.1 and 0.5 nmol of CGRP8-37 alone. The hyperalgesic effect of intra-nucleus accumbens administration of CGRP8-37 lasted for more than 60 min after the injection, suggesting that CGRP1 receptor is involved in anti-nociception in the nucleus accumbens of rats. The results indicate that CGRP and CGRP1 receptor have important roles in nociceptive modulation in the nucleus accumbens of rats.
本研究旨在探讨降钙素基因相关肽（CGRP）及其拮抗剂CGRP8 - 37在大鼠伏隔核伤害感受中的作用。通过热板法和Randall Selitto试验测量后爪对伤害性刺激的缩爪潜伏期（HWLs）。伏隔核内注射0.5或1 nmol的CGRP后，对热刺激和机械刺激的HWL均显著增加，但注射0.1 nmol时未出现此现象，这表明CGRP在大鼠伏隔核中发挥抗伤害感受作用。伏隔核内注射1 nmol的CGRP诱导的抗伤害感受作用，在随后伏隔核内注射1 nmol的CGRP8 - 37（CGRP1受体的选择性拮抗剂）后被显著阻断。此外，单独在伏隔核内注射0.02、0.1和0.5 nmol的CGRP8 - 37后，对热刺激和机械刺激的HWL均显著降低。注射后，伏隔核内注射CGRP8 - 37的痛觉过敏作用持续超过60分钟，提示CGRP1受体参与大鼠伏隔核的抗伤害感受。结果表明，CGRP和CGRP1受体在大鼠伏隔核的伤害感受调制中具有重要作用。
