降钙素基因相关肽对缺氧时大鼠海马培养神经元c—fos表达的影响

采用免疫组化（ABC）方法，观察缺氧诱导体外培养大鼠海马神经元c-fos的表达及降钙素基因相关肽（CGRP）的影响。结果显示，缺氧后海马神经元中Fos-免疫反应（Fos—IR）阳性胞核百分率随缺氧时间的延长而逐渐增多，图像分析的结果显示，缺氧后Fos—IR阳性胞核的平均失密度亦随缺氧时间的延长而逐渐增强。经CGRP孵育的海马神经元缺氧后Fos-IR阳性胞核的百分率和Fos-IR阳性胞核的平均光密度均明显低于非CGRP孵育组。本结果表明，缺氧能诱导体外培养海马神经元。c-fos的表达，神经肽CGRP能抑制缺氧海马神经元c-fos的表达。提示CGRP对海马神经元缺氧损伤可能具有一定保护作用。     

人重组白细胞介素—6对缺氧对后海马培养神经…

用免疫组化方法，观察缺氧诱导体外培养大鼠海马神经细胞Ｆｏｓ表达及人重组白细胞介素－６（ｒｈＩＬ－６＿的影响。结果显示，经ｒｈＩＬ－６卵育的海马神经细胞缺氧后Ｆｏｓ免疫反应一胸核的百分率和Ｆｏｓ反应阳性胸核的平均光密度均明显低于对照组，表明缺氧能诱导体外培养海马神经细胞Ｆｏｓ的表达，ｒｈＩＬ－６能抑制缺氧神经细胞Ｆｏｓ的表达。提示ｒｈＩＬ－６可能参与脑缺氧损伤的调控。     

人重组白细胞介素-6对大鼠海马神经元Bcl-2表达的影响

观察重组人白细胞介素－6（rhIL－6）对体外培养大鼠海马神经元Bcl－2表达的影响。方法取培养3、7、14、21和28天（d）的两组（对照组和rhIL－6组）培养神经元,分别观察其生长发育和神经元活存数,并用抗Bcl－2抗血清进行免疫组化染色,观察Bcl-2免疫反应（Bcl-2－IR）阳性和阴性神经元数目,计算Bcl-2－IR阳性神经元所占百分率,并在图像分析仪上对Bcl-2－IR神经元作平均光密度的色谱分析。结果培养3、7、14、21和28d时,rhIL－6组神经元活存数、Bcl－2－IR阳性神经元数和Bcl-2-IR阳性神经元的平均光密度均明显高于对照组。结论rhIL－6能增强生长发育过程中海马神经元Bcl-2的表达,减少神经元的退化死亡,表明rhIL-6对体外培养的海马神经元具有神经营养作用。     

LPS激发大鼠前脑神经元Fos和小胶质细胞OX42表达改变

目的 探讨单次腹腔注射LPS后前脑神经元和小胶质细胞的可塑性变化和相互关系。方法 应用抗Fos、抗TH或抗OX42单一、以及抗Fos／抗TH／抗OX42三重免疫组化标记方法，观察大鼠单次腹腔注射LPS后，Fos阳性神经元、Fos／TH阳性神经元、OX42阳性小胶质细胞在脑内的表达分布及时程变化，以及Fos阳性神经元或Fos／TH阳性神经元与OX42阳性小胶质细胞之间的关系。结果：Fos阳性神经元分布在额、顶皮质，扣带回和梨状皮质，外侧隔核腹侧部，杏仁中央核，海马CA2区、CA3区、齿状回，下丘脑室旁核、视上核、下丘脑外侧区和第三脑室周围灰质等。Fos阳性神经元在注射后30min出现表达，注射后1～3h为表达高峰。反应阳性小胶质细胞首先于脑室周围灰质出现，注射后6h达到高峰，胞体变大，突起变粗，OX42呈阳性深染，密集分布于Fos阳性神经元的表达区域。下丘脑Fos／TH／OX42三重染色切片显示：由LPS激活的Fos／TH阳性神经元周围被OX42阳性细胞包绕并接触，表明神经元和小胶质细胞在对LPS刺激的反应中关系密切。结论 在外周免疫刺激下，下丘脑、扣带回、梨状皮质和海马内的神经元和小胶质细胞可能参与免疫调节。     

缺氧对海马培养细胞人重组白细胞介素-6免疫组化反应的影响

本文观察了缺氧对体外培养海马细胞中rhIL-6免疫反应的影响。结果显示，体外培养的海马神经元和神经胶质细胞的rhIL-6呈弱阳性免疫反应，缺氧1～4h后神经元和神经胶质细胞的rhIL-6免疫组化反应明显增强。对免疫染色细胞作图像分析结果显示，缺氧后神经元和神经胶质细胞的平均光密度较缺氧前增加，尤以缺氧2h时最明显，之后随缺氧时间延长，神经元和神经胶质细胞的平均光密度又逐渐减弱。上述结果表明，海马脑区存在rhIL-6免疫反应细胞；缺氧条件下rhIL-6免疫组化反应增强，提示rhIL-6可能参与脑缺氧损伤的调控。     

低氧预处理对大鼠海马神经元缺氧耐性和热休克蛋白表达的影响

采用免疫组织化学方法,观察低氧预处理对大鼠海马培养神经元缺氧耐受性和热休克蛋白（Ｈsp70)表达的影响。结果显示,低氧预处理能诱导海马神经元对Ｈsp70的表达。经低氧预处理的海马神经元缺氧－复氧后Ｈsp70表达较对照组明显增强,神经元损伤程度减轻,神经元存活数明显高于对照组。本结果表明,低氧预处理可诱导海马培养神经元对Hsp７０的表达,并使海马神经元对缺氧产生耐受,减少缺氧－复氧后神经元的死亡。     

皮质酮对大鼠原代海马神经细胞的毒性作用

本文探讨了皮质酮（corticosterone，CORT）对大鼠原代海马神经细胞的毒性作用及作用机制。实验结果显示，CORT加入无血清DMEM培养基可剂量依赖地损伤原代培养海马神经细胞，LD50为3．2×10－6mol／L，而原代培养的皮层神经细胞只被高浓度皮质酮（10－5mol／L和10－4mol／L）所损伤，其LD50为8.5×10－5mol／L，比前者大近20倍。原代培养的海马神经细胞补充高浓度的葡萄糖或NMDA一受体拮抗剂MK－801可显著地拮抗CORT对海马神经细胞的毒性作用。同时，CORT处理的海马神经细胞胞内ATP水平明显降低，而补充高浓度葡萄糖（25mmol／L）可逆转CORT诱导的ATP耗竭。以上结果提示，CORT可选择地损伤海马神经细胞，这一损伤作用与葡萄糖浓度相关。实验结果进一步提示，CORT对海马神经细胞的毒性作用可能与其导致的能量水平低下和兴奋性氨基酸的堆积有关．     

人重组白细胞介素—6对培养的大鼠海马神经元缺氧—复氧后Jun表达的影响

近来的研究表明 ,Ｃ ｊｕｎ原癌基因为脑内即早反应基因 ,能被外界多种刺激因子诱导。低氧、缺血和某些药物等外源性刺激可诱导Ｃ ｊｕｎ表达[1] 。体外培养的交感神经元在去除神经生长因子的条件下可引起Ｃ ｊｕｎ表达增加 ,并证明Ｃ ｊｕｎ过度表达能导致神经元凋亡[2 ] 。但有关缺氧 复氧对体外培养海马神经元Ｊｕｎ表达影响的研究甚少。鉴于我们以前的工作证实人重组白细胞介素 6 (ｒｈＩＬ 6 )能增强海马神经元的抗缺氧能力[3 ] ,但ｒｈＩＬ 6能否影响缺氧 复氧后神经元的Ｊｕｎ表达尚不清楚 ,为此本实验用免疫组织化学方法 ,观察缺…     

低氧预处理对大鼠海马神经元缺氧耐受性和IL-6免疫反应的影响

目的 观察低氧预处理对大鼠海马神经元缺氧耐受性和IL-6免疫反应的影响。方法 取培养12d的两组（对照组和低氧预处理组）培养神经元,同时置于缺氧环境（0.9L/LN2、0.1L/LCO2)中培养2、4、8和12两组（对照组和低氧预处理组）培养神经元,同时置于缺氧环境（0.9L/LN2、0.1L/LCO2)中培养2、4、8和12h,分别观察它们的形态变化和神经元存活数,并用抗rhIL-6单克隆抗体进行免疫组化染色,观察缺氧对大鼠海马培养神经元IL-6免疫反应的影响。结果 低氧预处理可增强海马神经元对rhIL-6的免疫反应,经低氧预处理的海马神经元缺氧后神经元存活数和对rhIL-6的免疫反应均明显高于对照组。结论 低氧预处理氧预处理的海马神经元缺氧后神经元存活数和对thIL-6的免疫反应均明显高于对照组。结论 低氧预处理可使体外培养的海马神经元对缺氧产生耐受,其中rhIL-6的免疫反应增加可能是海马神经元对缺氧的一种适应性变化,提示IL-6可能参与脑缺氧耐受性的形成,并在海马神经元缺氧损伤的调控中起重要作用。     

L-NAME对大鼠局灶性脑缺血灌注损伤Fos蛋白表达的影响

目的观察一氧化氮含量的变化对缺血再灌注损伤后Fos蛋白表达的影响。方法采用线拴法制作大鼠局灶性脑缺血再灌注损伤模型,利用NADPH组化和Fos蛋白免疫组化双标技术研究NOS抑制剂L－NAME对大鼠局灶性脑缺血再灌注损伤脑皮层Fos蛋白表达的影响。结果缺血60min再灌注3h后损伤侧脑组织皮质一氧化氮合酶阳性神经元较正常增多并深染,Fos蛋白表达增加,L－NAME（3mg／kg）治疗组脑皮质神经元Fos蛋白的表达量较对照组减少,L－NAME（10mg/kg）治疗组脑皮质神经元Fos蛋白的表达量较对照组明显减少,同时也可见给予L－NAME后脑组织皮质内NOS阳性神经元无论在数量上还是在细胞着色、胞体突起均明显减少。结论c－fos基因表达也可能部分参与了NO的致神经细胞损伤过程。     

缺氧-复氧对大鼠海马培养神经元Bcl-2、Bax表达和神经元凋亡的影响

目的 观察缺氧-复氧对体外培养海马神经元Bcl-2和Bax表达和神经元凋亡的影响。方法 取培养12d的海马神经元，置于恒温(36℃)密闭容器内，连续充以无氧气体[90％(体积分数)N2、10％(体积分数)CO2]，在缺氧条件下继续培养4h后，再于常氧培养箱内复氧培养24h和72h。于不同时间观察神经元存活数，并分别用抗Bcl-2和Bax抗血清进行免疫组织化学染色，观察缺氧-复氧后大鼠海马培养神经元Bcl-2和Bax表达。并用原位末端标记(TUNEL)法和流式细胞术分别检测缺氧-复氧对体外培养海马神经元凋亡的影响。结果 缺氧-复氧后24～72h,海马神经元对Bcl-2的表达逐渐减弱，对Bax的表达逐渐增强，对Bax／Bcl-2比值逐渐增大，凋亡神经元百分率逐渐增多。结论 缺氧-复氧后24～72h神经元凋亡的发生与神经元Bcl-2表达逐渐减弱，Bax表达逐渐增强，Bax／Bcl-2比值逐渐增大有关。     

人重组白细胞介素-6可减少缺氧-复氧后大鼠海马培养神经元的DNA损伤

用原位末端标记（ＴＵＮＥＬ）法观察人重组白细胞介素－６（ｒｈＩＬ－６）对缺氧－复氧后大鼠海马培养神经元的ＤＮＡ损伤的影响。结果显示,海马神经元缺氧－复氧后ＤＮＡ损伤神经元百分率明显增高,经ｒｈＩＬ－６ 预处理的海马神经元缺氧－复氧后ＤＮＡ损伤神经元百分率明显低于对照组。本结果表明,缺氧－复氧能使体外培养海马神经元发生ＤＮＡ损伤,ｒｈＩＬ－６ 可减少缺氧－复氧后海马神经元的ＤＮＡ损伤。提示ｒｈＩＬ－６ 对海马神经元缺氧－复氧损伤可能具有一定保护作用。     

Hypotension preferentially induces c-fos immunoreactivity in supraoptic vasopressin neurons.

Immunoreactivity to Fos protein (Fos-IR) was detected in rat hypothalamic neurons within 1 h of onset of hemorrhage by withdrawing 4-5 ml of blood, which lowered the arterial blood pressure to 50-70 mm Hg. About 70% of vasopressin (AVP)-containing neurons in the supraoptic nucleus (SON) and 20% in the paraventricular nucleus (PVN) expressed Fos-IR. In contrast, 5% of oxytocin (OXY)-containing neurons in the SON and < 1% in PVN were Fos-IR. Intravenous infusion of the vasodilating agent, nitroprusside, which lowered the blood pressure to levels comparable to that attained by hemorrhage, induced Fos-IR in greater than 65% of AVP-containing neurons in the SON, while relatively few AVP neurons in the PVN were Fos positive. These results suggest that hemorrhage or hypotension preferentially induces c-fos expression in supraoptic AVP-containing neurons.     

低氧预处理对大鼠海马神经元缺氧耐受性和热休克蛋白表达的影响

采用免疫组织化学方法 ,观察低氧预处理对大鼠海马培养神经元缺氧耐受性和热休克蛋白(Hsp70 )表达的影响。结果显示 ,低氧预处理能诱导海马神经元对Hsp70的表达。经低氧预处理的海马神经元缺氧 复氧后Hsp70表达较对照组明显增强 ,神经元损伤程度减轻 ,神经元存活数明显高于对照组。本结果表明 ,低氧预处理可诱导海马培养神经元对Hsp70的表达 ,并使海马神经元对缺氧产生耐受 ,减少缺氧 复氧后神经元的死亡     

Increased c-fos expression in spinal lumbosacral projection neurons and preganglionic neurons after irritation of the lower urinary tract in the rat.

Chemical irritation of the lower urinary tract (LUT) induces c-fos expression in neurons in the lumbosacral (L(6) and S(1)) spinal cord. This study used axonal tracing with fluorescent dyes to identify the types of spinal neurons expressing Fos immunoreactivity (IR) after LUT irritation in the rat. Fos-IR was detected in lateral and medial superficial dorsal horn, the sacral parasympathetic nucleus (SPN) and lamina X around the central canal. Fos-IR was detected in spinal neurons projecting to supraspinal sites (brainstem and hypothalamus), in preganglionic neurons (PGN) and in unlabeled segmental interneurons. A substantial percentage (20%) of dye labeled PGN exhibited Fos-IR after LUT irritation; and a larger percentage (36%) exhibited Fos-IR after electrical stimulation of the pelvic nerve which contains afferent pathways from all of the pelvic organs. The majority (average 55%) of Fos-positive neurons projecting to supraspinal sites were also located in the region of the SPN. A selective distribution of different types of neurons was detected in this region: PGN were located ventral to the spinal projection neurons which in turn were located ventral to the majority of unidentified Fos-positive neurons. The distribution of Fos-positive PGN and projection neurons was similar in spinal intact and spinal transected animals indicating that c-fos expression was mediated by monosynaptic afferent input or input from segmental interneurons and was not due to activation of supraspinal micturition reflex pathways.     

Increased c-fos expression in spinal lumbosacral projection neurons and preganglionic neurons after irritation of the lower urinary tract in the rat

Chemical irritation of the lower urinary tract (LUT) induces c-fos expression in neurons in the lumbosacral (L₆ and S₁) spinal cord. This study used axonal tracing with fluorescent dyes to identify the types of spinal neurons expressing Fos immunoreactivity (IR) after LUT irritation in the rat. Fos-IR was detected in lateral and medial superficial dorsal horn, the sacral parasympathetic nucleus (SPN) and lamina X around the central canal. Fos-IR was detected in spinal neurons projecting to supraspinal sites (brainstem and hypothalamus), in preganglionic neurons (PGN) and in unlabeled segmental interneurons. A substantial percentage (20%) of dye labeled PGN exhibited Fos-IR after LUT irritation; and a larger percentage (36%) exhibited Fos-IR after electrical stimulation of the pelvic nerve which contains afferent pathways from all of the pelvic organs. The majority (average 55%) of Fos-positive neurons projecting to supraspinal sites were also located in the region of the SPN. A selective distribution of different types of neurons was detected in this region: PGN were located ventral to the spinal projection neurons which in turn were located ventral to the majority of unidentified Fos-positive neurons. The distribution of Fos-positive PGN and projection neurons was similar in spinal intact and spinal transected animals indicating that c-fos expression was mediated by monosynaptic afferent input or input from segmental interneurons and was not due to activation of supraspinal micturition reflex pathways.