延髓孤束核区微量注射组胺的呼吸效应

The Respiratory Response to Histamine Applied by Microinjection into the Nucleus Tractus Solitarius Of Medulla Oblongata

在35例麻醉、迷走神经切断和自主呼吸的家兔,记录膈神经放电,观察延髓孤束核区(NTS区)微量注射组胺(HA)对呼吸的影响。结果发现:(1)NTS区微量注射HA后,动物呼吸频率明显增快,膈神经放电积分幅度减小;(2)HA的呼吸效应可被H_1受体阻断剂扑尔敏阻断,但不能被H_2受体阻断剂甲氰咪胍阻断;(3)在NTS区单独注射H_1或H_2受体阻断剂对呼吸频率和膈神经放电积分幅度均无影响。这些结果提示,HA对NTS区的吸气神经元具有兴奋性调制作用,此种作用是通过H_1受体实现的。

The respiratory changes following microinjection of histamine (HA) into theNucleus Tractus Solitarius (NTS) of medulla oblongata were studied in 35 anesthetized,vagotomized and spontaneously breathing rabbits by recording the phrenic nerve firing. Itwas found that (1) Microinjection of HA stimulated the frequency of respiration withdiminution of the phrenic nerve firing integration. (2)H_1 receptor blocker-chloropheniraminbut not H_2 receptor blocker-cimetidine could block the HA-induced respiratoryresponse. (3) Microinjection of H_1 or H_2 blocker alone into the NTS did not affect thenormal spontaneous respiratory frequency and phrenic nerve firing. It suggests thathistamine has an excitatory modulation on the inspiratory neurons in NTS which is mediatedby H_1 receptors.