Xiong Wei, Yu Long-Chuan
Laboratory of Neurobiology and The National Laboratory of Biomembrane and Membrane Biotechnology, College of Life Science, Peking University, Beijing 100871, China.
Behav Brain Res. 2006 Oct 2;173(1):116-21. doi: 10.1016/j.bbr.2006.06.010. Epub 2006 Jul 11.
Cholecystokinin (CCK) is an endogenous anti-opioid peptide in the central nervous system. The present study investigated the effects of endogenous CCK on tolerance to morphine antinociception in the nucleus accumbens (NAc) of rats. Chronic administration of morphine to NAc induced marked tolerance to antinociception. Intra-NAc administration of the CCK2 receptor antagonist LY225910 inhibited not only the development but also the expression of chronic morphine-induced antinociceptive tolerance. However, intra-NAc injection of LY225910 did not influence the antinociception induced by intra-NAc administration of morphine in the intact rats. The results indicate that endogenous CCK plays an important role in morphine-induced antinociceptive tolerance in the NAc of rats.
胆囊收缩素（CCK）是中枢神经系统中的一种内源性抗阿片肽。本研究调查了内源性CCK对大鼠伏隔核（NAc）中吗啡镇痛耐受性的影响。向NAc慢性注射吗啡可诱导出明显的镇痛耐受性。向NAc内注射CCK2受体拮抗剂LY225910不仅抑制了慢性吗啡诱导的镇痛耐受性的形成，还抑制了其表达。然而，在完整大鼠中，向NAc内注射LY225910并不影响向NAc内注射吗啡所诱导的镇痛作用。结果表明，内源性CCK在大鼠NAc中吗啡诱导的镇痛耐受性中起重要作用。
