Central peptidergic regulatory mechanims of sympatho-adrenomedullarly functions.

研究了氨基甲酸乙酯麻醉大鼠交感神经-肾上腺髓核功能的中枢调节机制。得到的结果如下：脑室内（ICV）给药bombesin提高血浆去甲肾上腺素（NA）和肾上腺素（Ad）的水平，电记录的神经活动从内脏神经的交感和肾上腺分支。另一方面，前列腺素（PG） E2通过相同的途径选择性地升高NA的血浆水平和交感神经的神经活动，而不是肾上腺支。2) PGE2提高血浆NA水平的作用是通过激活脑内EP3受体实现的。3)免疫信号介质白细胞介素1 β (il -1 β)选择性地升高血浆NA水平，但不升高AD水平，PGE2.4)糖皮质激素（bombesin）和il -1 β对血浆NA和AD水平的影响可以通过加PG合成抑制剂吲哚美辛（indomethacin）的ICV预处理消除。5)从一氧化氮（NO）合成酶抑制剂L-NAME和NO清除剂exyhemoglobin的结果来看，il -1 β在脑内产生的NO可能介导了细胞因子诱导的血浆NA水平升高。这些结果表明，大脑中可能存在两种不同类型的神经元细胞；一个神经元细胞群的激活同时刺激交感神经系统和肾上腺髓系统，而另一个神经元细胞群的激活选择性地只刺激交感神经系统。脑内bombesin受体位于前一神经元细胞群，il -1 β受体位于后一神经元细胞群。脑内由bombesin和il -1 β产生的pg可能参与了这些神经元细胞群的激活。

Central regulatory mechanisms of sympatho-adrenomedullaryl functions were examined in rats under urethane anesthesia. Results obtained are as follows : Intracerebroventricular (ICV) administration of bombesin elevated plasma levels of both noradrenaline (NA) and adrenaline (Ad), and nerve activities electrically recorded form both the sympathetic and adrenal branches of the splanchinic nerves. On the other hand, prostaglandin (PG) E2 by the same route selectively elevated the plasma level of NA alone, and nerve activity of the sympathetic but not the adrenal branch. 2) The effect of PGE2 to elevate the plasma level of NA was due to its activation of EP3 receptors in the brain. 3) Interleukin 1beta (IL-1beta), a madiator of immune signals, selectively elevated the plasma level of NA but not AD,as observed with PGE2.4) The effects of bombesin and IL-1beta on the plasma levels of NA and Ad were abolished by ICV pretreatment with indomethacin, an inhibitor of PG synthesis. 5) From the results with L-NAME,an inhibitor of nitric oxide (NO) synthetase, and exyhemoglobin, an NO scavenger, NO produced in the brain by IL-1beta probably mediates this cytokine-induced elevtion of plasma level of NA.From these results, it is suggested that two different types of neuronal cells probbly exist in the brain ; activation of one neuronal cell group ecxites both the sympathetic and adrenomedullarly systems, while activation of the other neuronal cell group selectively excites the sympathetic system alone. Receptors of bombesin are located on the former neuronal cell group, while those of IL-1beta are located on the latter neuronal cell group in the brain. PGs in the brain produced by bombesin and IL-1beta are probably involved in activation of these neuronal cell groups.