本研究应用大鼠下丘脑正中隆起(ME),观察 γ-氨基丁酸(GABA)和去甲肾上腺素(NA)对下丘脑促黄体生成激素释放激素(LHRH)神经元末梢分泌作用的影响。结果发现:GABA(10^(-6)mol/L)可显著促进 ME 的 LHRH 和 NA 的释放,即 LHRH 释放量由27.3...本研究应用大鼠下丘脑正中隆起(ME),观察 γ-氨基丁酸(GABA)和去甲肾上腺素(NA)对下丘脑促黄体生成激素释放激素(LHRH)神经元末梢分泌作用的影响。结果发现:GABA(10^(-6)mol/L)可显著促进 ME 的 LHRH 和 NA 的释放,即 LHRH 释放量由27.3±2.5pg/100ul 增加至150.4±27.9pg/100μl;NA 释放量由50.9±4.2pg/100μl 增加至105.5±19.1pg/100ul,两者与对照组相比有显著差异(P<0.01)。GABA 这些作用可被受体拮抗剂荷包牡丹碱(Bicuculline)所翻转。当荷包牡丹碱和 GABA(10^(-6)mol/L)同时存在于 ME 的培灌液中,LHRH 的分泌量下降为18.2±1.9pg/100μl,而 NA 分泌量下降为43.9±3.4pg/100μl。在内源性 NA 被利血平耗竭时,LHRH 的释放量仅增加26.5%,而 GABA 能使正常大鼠 LHRH 释放量增加451.9%。本研究提示:GABA 可促进下丘脑 ME 释放 LHRH,这一作用可能通过 NA 中介。展开更多
采用了AtlantisC18反相色谱柱(适用于分离极性分子的反相色谱柱),成功地分离了去甲肾上腺素(NA),肾上腺素(A),多巴胺(DA)等儿茶酚胺(CAs)类物质,研究了CAs在Atlantis C18和Novle pak C18柱的保留特性,比较了流动相中离子对试剂辛烷基磺...采用了AtlantisC18反相色谱柱(适用于分离极性分子的反相色谱柱),成功地分离了去甲肾上腺素(NA),肾上腺素(A),多巴胺(DA)等儿茶酚胺(CAs)类物质,研究了CAs在Atlantis C18和Novle pak C18柱的保留特性,比较了流动相中离子对试剂辛烷基磺酸钠(B8)浓度对CAs容量因子k’的作用,确认采用AtlantisC18柱分离CAs,色谱条件优化空间更大,更适于复杂生物样品分析。色谱条件:Atlantis C18柱,电化检测,流动相:NaH2PO450 mmol/L、柠檬酸钠50 mmol/L缓冲液-乙腈(体积比(75∶25),检测限(S/N=2)在0.93—2.43pg,绝对回收率均在98.02%以上,样品日内RSD1.5%以下。方法精密、准确。展开更多
Central inhibition, discovered by Sechenov in 1862, suggests that electrically stimulating the forebrain or medulla oblongata in frog generally suppresses reflexes. However, the underlying molecular mechanisms are sti...Central inhibition, discovered by Sechenov in 1862, suggests that electrically stimulating the forebrain or medulla oblongata in frog generally suppresses reflexes. However, the underlying molecular mechanisms are still unclear. Using ethanol (EtOH), noradrenalin (NA), and other neurotransmitters in thalamic preparations, Sechenov inhibition was stimulated in Bufo toads in this study. The result showed that, similar to Sechenov inhibition, the acute application of EtOH or NA excited the thalamus and prolonged the latency of withdrawal reflex. Our study evidences the involvement of α-adrenoceptors in such central inhibition, and explains the role of acute EtOH application in the in- duction of reflex inhibition.展开更多
文摘本研究应用大鼠下丘脑正中隆起(ME),观察 γ-氨基丁酸(GABA)和去甲肾上腺素(NA)对下丘脑促黄体生成激素释放激素(LHRH)神经元末梢分泌作用的影响。结果发现:GABA(10^(-6)mol/L)可显著促进 ME 的 LHRH 和 NA 的释放,即 LHRH 释放量由27.3±2.5pg/100ul 增加至150.4±27.9pg/100μl;NA 释放量由50.9±4.2pg/100μl 增加至105.5±19.1pg/100ul,两者与对照组相比有显著差异(P<0.01)。GABA 这些作用可被受体拮抗剂荷包牡丹碱(Bicuculline)所翻转。当荷包牡丹碱和 GABA(10^(-6)mol/L)同时存在于 ME 的培灌液中,LHRH 的分泌量下降为18.2±1.9pg/100μl,而 NA 分泌量下降为43.9±3.4pg/100μl。在内源性 NA 被利血平耗竭时,LHRH 的释放量仅增加26.5%,而 GABA 能使正常大鼠 LHRH 释放量增加451.9%。本研究提示:GABA 可促进下丘脑 ME 释放 LHRH,这一作用可能通过 NA 中介。
基金the Major State Basic Research Development Program of China (973 Program) (Grant No. 2005CB522503)
文摘Central inhibition, discovered by Sechenov in 1862, suggests that electrically stimulating the forebrain or medulla oblongata in frog generally suppresses reflexes. However, the underlying molecular mechanisms are still unclear. Using ethanol (EtOH), noradrenalin (NA), and other neurotransmitters in thalamic preparations, Sechenov inhibition was stimulated in Bufo toads in this study. The result showed that, similar to Sechenov inhibition, the acute application of EtOH or NA excited the thalamus and prolonged the latency of withdrawal reflex. Our study evidences the involvement of α-adrenoceptors in such central inhibition, and explains the role of acute EtOH application in the in- duction of reflex inhibition.
