地塞米松对去甲肾上腺素在孤束核引起的心血管活动的影响

目的：研究糖皮质激素对去甲肾上腺素在孤束核对心血管活动调节的影响。方法：向内侧和中间内侧孤束（ＮＴＳ）微量注射地塞米松（Ｄｅｘ）去甲肾上腺素（ＮＥ），米非司酮及荷包牡丹碱（Ｂｉｃ）观察它们引起的心血管活动的变化。结果：Ｄｅｘ（０．３９ｍｍｏｌ．Ｌ＾－１，０．１μＬ）可以消除１０ｍｉｎ后在同一区域性注射ＮＥ（８ｍｍｏｌ．Ｌ＾－１，０．１μＬ）所引起的血压下降，心率减慢的效应，这种抑制作用４ｈ内不消失

Effect of dexamethasone on cardiovascular response induced by norepinephrine in nucleus tractus solitarii.

AIM: To study the effect of dexamethasone on cardiovascular response induced by norepinephrine (NE) in nucleus tractus solitarii (NTS). METHODS: The variations of cardiovascular action caused by these drugs were observed after injection of mifepristone (Mif), dexamethasone (Dex), bicuculline (Bic), and NE into the medial and intermediate NTS. RESULTS: Microinjection of Dex (0.39 mmol.L-1, 0.1 microL) into the medial and intermediate NTS abolished the vasodepressed response to NE (8 mmol.L-1, 0.1 microL) microinjected into the same area 10 min later, and the inhibition did not disappear until 4 h. The rapid inhibitory effects of Dex on NE vasodepression was not antagonized by Mif (4.66 mumol.L-1, 0.1 microL), but it was blocked by Bic (3.24 mumol.L-1, 0.1 microL). CONCLUSION: Dex abolished cardiovascular response to NE microinjected into NTS which may be mediated by GABAA receptor.