【摘要】 <正> 已经证明,P物质(简称SP)是一种肽类神经递质,对躯体痛觉的调节有重要作用。本文检测了SP对内脏痛反应的作用。 材料和方法 选用250～300克的雄性大鼠。部分动物实验前分别在中脑导水管周围灰质(简称PAG,Ap~+6.5,SD0.5～1,V~-5.5～6)以及PAG外侧1～2mm(SD2～3,其它参数同前)埋置外径0.75mm的不锈钢套管。大鼠活动恢复正常后,在麻醉下于腹膜后分离左侧内脏大神经,阻断其外周传导功能,在中枢端埋置保护刺激电极。以电刺激内脏大神经中枢端模拟内脏痛。置左颈动脉插管以观察血压动态。大鼠完全清醒后,更多还原

【Abstract】 Depressive effects of Substance P (SP) on visceral pain in rats were studied. Visceral pain was mimicked by electrical stimulation of the proximal end of the left nervous splanchnicus major. The latent period of struggle response of rat for pain was regarded as the threshold of visceral pain.Intraperitoneal injection of SP 100μg/rat or intracerebral administration of SP 5μg(μl),via chronically indwelling canulae placed in the mid-brain periaqueductal gray matter (PAG), caused an obvious and prolonged increase of visceral pain threshold of rat. The increase of visceral pain threshold of rat produced by intraperitoneal SP was partially reversed by Naloxone injection 1μg(μl) into bilateral PAG.Results suggested that:1) SP had a potent analgesic effect on visceral pain; 2) PAG was the important structure on which SP acted; 3) such depression might be referred to morphin receptors in PAG.更多还原