探讨神经肽Y(NPY)在SD大鼠中脑导水管周围灰质(PAG)对伤害性刺激反应的作用。应用热板和机械压力实验法,以大鼠后爪缩爪反应潜伏期(PWL)为痛阈指标,观察PAG内微量注射NPY对PWLs的影响。PAG内注射0.05、0.1、0.2 nmol NPY均显著地增加慢性神经痛大鼠的双侧PWLs,且呈量效关系。NPY引起的PWLs增加可被Y_(1)受体拮抗剂和阿片受体拮抗剂所阻断。结果显示,在大鼠PAG微量注射NPY可产生明显的镇痛作用。
关键词： paw withdrawal latency; periaqueductal grey; neuropeptide Y; naloxone; noxious stimulation
Microinjection of neuropeptide Y into periaqueductal grey produces anti-nociception in rats with mononeuropathy
Department of Physiology,Linyi Medical College.Linyi 276002,Shandong
The present study was carried out to investigate the effects of neuropeptide Y (NPY) in the midbrain periaqueductal grey (PAG) on the nociceptive modulation in mononeuropathic rats. NPY was microinjected into the PAG. The latency of paw withdrawal (PWL), assessed by the hot-plate (52℃) and the Randall Selitto test, was measured. Intra-PAG administration of 0.05, 0.1 and 0.2 nmol of NPY significantly increased the PWLs in a dose-dependent manner. Co-administration of 0.2 nmol of NPY_(28-36) and 5.5 nmol of naloxone significantly attenuated the NPY-induced increase in PWLs. The results suggested that Y_(1) receptor may mediate NPY-induced anti-nociception, and that the opioid receptors in PAG may also be involved in this process in mononeuropathic rats.
Key words: 缩爪反应潜伏期;导水管周围灰质;神经肽Y;纳洛酮;伤害性刺激
王加真. 中脑导水管周围灰质内微量注射神经肽Y减弱慢性神经痛大鼠对伤害性刺激的反应[J]. 生理学报 2004; 56 (1): .
Wang Jiazhen. Microinjection of neuropeptide Y into periaqueductal grey produces anti-nociception in rats with mononeuropathy. Acta Physiol Sin 2004; 56 (1): (in Chinese with English abstract).