丁基苯酞对氯化钾及 N-甲基-D-门冬氨酸诱导的大鼠皮质神经细胞损伤的保护作用

用原代培养大鼠皮质神经细胞的方法，观察ｌ丁基苯酞（ｌＮＢＰ）和ｄ丁基苯酞（ｄＮＢＰ）对ＫＣｌ及Ｎ甲基Ｄ门冬氨酸（ＮＭＤＡ）诱导的大鼠皮质神经细胞损伤的保护作用。结果表明：ｌＮＢＰ和ｄＮＢＰ能剂量依赖性地抑制ＮＭＤＡ诱导的大鼠皮质神经细胞内乳酸脱氢酶的释放，降低细胞死亡率，改善受损细胞的形态；此外ｌＮＢＰ和ｄＮＢＰ还能明显减轻ＫＣｌ诱导的神经细胞损伤。提示：ｌＮＢＰ和ｄＮＢＰ对ＫＣｌ及ＮＭＤＡ诱导的大鼠皮质神经细胞损伤有明显保护作用。     

丁基苯酞对原代培养胎大鼠皮层神经细胞外液NO及胞浆内cGMP水平的影响

用分光光度法和放射免疫分析法分别检测NO及cGMP水平,同时观察l-丁基苯酞(l-NBP)和d-丁基苯酞(d-NBP)对原代培养的胎大鼠皮层神经细胞外液NO及胞浆内cGMP水平的影响。结果表明,d-NBP(0.1～100μmol·L^-1)对低糖低氧条件下或含N-甲基-D-门冬氨酸(NMDA)或含KCl的培养基中皮层神经细胞外液NO及细胞内cGMP水平明显升高,而l-NBP(0.1～100μmol·L^-1)则能明显降低NO和cGMP水平。提示:d-NBP和l-NBP对低糖低氧,NMDA或KCl诱导的NO释放和cGMP生成有相反的作用。     

丁基苯酞对低糖低氧诱导的大鼠皮层神经细胞损伤的保护作用

为进一步探讨丁基苯肽对神经的保护作用,用原代培养大鼠皮层神经细胞的方法,以LDH和细胞形态等指标,观察了l-丁基苯酞(l-NBP)和d-丁基苯酞(d-NBP)对低糖低氧诱导的大鼠皮层神经细胞损伤的保护作用。结果表明:l-NBP和d-NBP能剂量依赖性地抑制低糖低氧诱导的大鼠皮层神经细胞内LDH的释放,降低细胞死亡率,并能改善受损细胞的形态;此外还能明显减轻低糖低氧诱导的神经细胞内粗面内质网脱颗粒及多聚核糖体解聚。提示:NBP对低糖低氧诱导的大鼠皮层神经细胞损伤有明显保护作用。     

脑室注射N-甲基-D-门冬氨酸对小鼠学习记忆的影响

采用一次性被动回避性条件反射方法,给小鼠icv N-甲基-D-门冬氨酸(NMDA)10,1和0.1 ng。结果表明:对正常小鼠,在跳台法中NMDA 10 ng能明显增强记忆巩固过程,在避暗法中NMDA 1 ng能显著增强记忆再现过程;在两种方法中,NMDA 1 ng均能显著改善乙醇及亚硝酸钠所致记忆障碍;而NMDA对记忆获得过程无影响。进一步研究表明,NMDA改善记忆的作用可被其受体特异性拮抗剂AP5所拮抗。结合以前报道和电生理研究结果提示,谷氨酸受体NMDA亚型在记忆过程中起着重要的作用,脑室给药作用的环节主要是影响记忆巩固和再现过程。     

氟哌啶醇对大鼠离体海马脑片和原代神经元缺糖/缺氧和N-甲基-D-天冬氨酸损伤的保护作用

目的观察氟哌啶醇对大鼠离体海马脑片和原代神经元的缺糖/缺氧(OGD)和N-甲基-D-天冬氨酸(N-methyl-D-aspartate,NMDA)损伤的潜在保护作用及其机制。方法海马脑片OGD以无葡萄糖的人工脑脊液中通95% N₂+5% CO₂诱导。通过测定TTC染色后形成的红色产物来分析脑片活性。结果氟哌啶醇(1和10 μmol·L^-1)抑制OGD损伤,抑制率分别为17.7%和25%,而D₂多巴胺受体拮抗剂多潘立酮无此作用。NMDA也能显著降低海马脑片及原代神经元的活性,而氟哌啶醇可抑制这一损伤作用。结论氟哌啶醇对大鼠离体海马脑片OGD和原代神经元NMDA损伤有保护作用。     

丁基苯酞抑制低氧低糖诱导的大鼠皮质神经细胞凋亡

目的：以原代培养的大鼠胎鼠皮质神经元低氧低糖再复氧为模型,研究丁基苯酞对神经细胞凋亡的抑制作用。方法：用流式细胞术检测DNA含量及凋亡细胞百分率,透射电镜观察细胞形态学变化,DNA琼脂糖凝胶电泳和原位末段标记(TUNEL)检测DNA断裂。 结果：丁基苯酞能减轻细胞核形态的改变,减少DNA断裂和阳性细胞数,使低氧低糖诱导的神经细胞凋亡百分率明显下降,凋亡峰显著降低。 结论：丁基苯酞对低氧低糖诱导的大鼠皮质神经细胞凋亡有抑制作用。     

脑室注射硝普钠、L-精氨酸、NG-硝基-L-精氨酸对清醒状态大鼠心血管活动的影响

给大鼠侧脑室内注射(icv)硝普钠(SNP)、NO的前体物质L-精氨酸(L-Arg)和精-精二肽(Arg-Arg),NO合成酶(NOS)抑制剂N^G-硝基-L-精氨酸(NNLA),观察清醒状态大鼠血压和心率的变化,探讨脑内NO对清醒状态大鼠心血管活动的调节作用。实验结果表明,icvSNP(8,16,32μg)使血压升高,并呈剂量效应关系,同时使心率加快。icvL-Arg(200μg)或不同剂量的精-精二肽也使血压升高,心率加快;icvNNLA(100μg)则使血压下降,心率减慢。以上结果提示,在一定范围内提高脑内NO,对心血管活动有正性调节作用,降低脑内NO则对心血管活动有负性调节作用。     

L-和DL-正丁基东莨菪碱对大鼠子宫作用的比较

用放射配基结合法测定L-正丁基东莨菪碱，DL-正丁基东莨菪碱与阿托品对大鼠子宫M 胆碱受体的亲和力。结果表明，L-与DL-正丁基东莨菪碱对大鼠子宫M胆碱受体的亲和力十分相近，但都比阿托品弱。比较L-正丁基东莨菪碱、DL-正丁基东莨菪碱和阿托品对离体大鼠子宫的影响及对抗乙酰胆碱所致的子宫收缩作用，表明两种正丁基东莨菪碱对离体大鼠子宫无影响，而能对抗乙酰胆碱所致的子宫收缩，且作用相近，但都比阿托品弱。说明生物效应与其受体亲和力的大小相关。     

丁基苯酞抗大鼠大脑皮质神经元氧糖剥夺/复氧损伤及其机制

本研究探讨丁基苯酞抗大鼠大脑皮质神经元氧糖剥夺/复氧损伤及其机制。原代培养大鼠大脑皮质神经元，建立氧糖剥夺/复氧模型(OGD/R)，采用MTT法、酶学检查、免疫组化、RT-PCR等观察丁基苯酞(各浓度组)的保护作用及其机制。在氧糖剥夺4 h/复氧8 h时丁基苯酞各浓度组可增加神经元的细胞活力和减少神经元LDH(乳酸脱氢酶)的释放，可显著降低神经元表达iNOS mRNA(诱生型一氧化氮合酶)和NF-κB(核因子κB) p65蛋白(增加)。不同剂量丁基苯酞(100、 10、 1和0.1 μmol·L^-1)在增加细胞活力、减少LDH释放及降低神经元表达iNOS mRNA等方面，高浓度的作用强于低浓度，且丁基苯酞100 μmol·L^-1组与吡咯烷二硫代氨基甲酸酯(pyrrolidine dithiocarbamate，PDTC) 100 μmol·L^-1组差异显著。在OGD 4 h/R 8 h时丁基苯酞可能抑制iNOSmRNA的表达及NF-κB的活化，从而有效保护氧糖剥夺/复氧中损伤的大脑皮质神经元。     

丁基苯酞对局部脑缺血大鼠神经元迟发性损伤及细胞内钙的影响

观察了丁基苯酞(NBP)对局部脑缺血迟发性脑梗塞和神经功能缺损的影响。结果表明,大鼠大脑中动脉阻断(MCAO)后2h分别poNBP80,160和240mg·kg^-1,均能明显降低脑梗塞面积,抑制率分别为49.0%,69.5%及85.1%,并明显改善神经功能缺失。在MCAO前1h予防给NBP(160mg·kg^-1po),也可明显缩小脑梗塞面积和改善神经功能缺失;在MCAO前连续口服7d,NBP剂量为80mg·kg^-1·d^-1,对上述指标均有改善作用。NBP对高K⁺引起大鼠脑突触体内Ca²⁺含量升高无影响。以上结果提示NBP对迟发性神经元损伤有保护作用。     

(-)-S·R-蝙蝠葛苏林碱对谷氨酸引起的大鼠大脑皮质神经元损伤的保护作用

用细胞培养方法,在原代培养的大鼠皮质神经细胞上,观察了(-)-S·R-蝙蝠葛苏林碱对谷氨酸引起的神经元损伤的保护作用。以Fura-2/AM为Ca²⁺的荧光指示剂,用AR-CM-MIC阳离子测定系统观察(-)-S·R-蝙蝠葛苏林碱对谷氨酸诱发大鼠脑皮质神经细胞内Ca²⁺升高的影响。结果表明(-)-S·R-蝙蝠葛苏林碱能剂量依赖性地抑制谷氨酸的神经毒作用,对谷氨酸诱发的神经细胞内游离Ca²⁺升高有明显的抑制作用。提示蝙蝠葛苏林碱对缺血性脑损伤有保护作用。     

Protective effect of oral -arginine administration on gentamicin-induced renal failure in rats

We investigated the effects of orally supplemented -arginine, the substrate of nitric oxide (NO) and N^ω-nitro- -arginine methyl ester ( -NAME), a nitric oxide-synthase inhibitor in gentamicin-induced renal failure. Rats were given gentamicin (100 mg/kg/day s.c.), gentamicin and -arginine (2 g/l, drinking water), gentamicin and -NAME (100 mg/l, drinking water) or gentamicin plus -arginine and -NAME. After 8 days, the gentamicin group developed marked renal failure, characterized by a significantly decreased creatinine clearance and increased blood creatinine, fractional excretion of sodium, fractional excretion of lithium, urine gamma glutamyl transferase, systolic blood pressure and daily urine volume when compared to controls. Renal histological analysis confirmed tubular necrosis. -arginine administration caused normalization of these parameters, whereas -NAME led to aggravation of the failure. Concomittant administration of -NAME and -arginine to gentamicin-treated rats caused no significant changes when compared to the rats receiving gentamicin alone. We conclude that -arginine supplementation has beneficial effects in gentamicin-induced renal failure in rats and that these effects are reversed by the NO-synthase inhibitor, -NAME.     

Glycogen synthase kinase-3 inhibitors prevent caspase-dependent apoptosis induced by ethanol in cultured rat cortical neurons

The effect of ethanol on cell viability was examined in rat cultured cortical neurons. Ethanol induced apoptosis, which was characterized by cell shrinkage, nuclear condensation or fragmentation and internucleosomal DNA fragmentation. Ethanol-induced apoptosis was prevented by N-methyl-d-aspartate (NMDA), an agonist of the NMDA receptor, which is a subtype of ionotropic glutamate receptors. Incubation with glycogen synthase kinase-3 (GSK-3) inhibitors 3-(2,4-dichlorophenyl)-4-(1-methyl-1H-indol-3-yl)-1H-pyrrole-2,5-dione (SB216763) and alsteropaullone, but not a cyclin-dependent protein kinase 5 inhibitor roscovitine, completely protected the neurons from ethanol-induced apoptosis. Apoptosis was accompanied by the activation of caspase-3 and prevented by a caspase-3 inhibitor. These results suggest that ethanol induces caspase-dependent apoptosis mediated by glycogen synthase kinase-3 activation in cultured rat cortical neurons.     

含L-4-氧代赖氨酸和N3-(4-甲氧基富马酰)-L-2,3-二氨基丙酸寡肽类似物的合成及其抗白念珠菌活性

运用“违法传递”概念,根据白念珠菌对寡肽的传送特点,设计并合成了8个含L-4-氧代赖氨酸(以下称I-677)和N³-(4-甲氧基富马酰)-L-2,3-二氨基丙酸(以下称FMDP)的寡肽类似物,均系新化合物。体外抗白念珠菌试验表明:I-677-FMDP-肽(I-677-FMDP,I-677-AA-FMDP,其中AA=Nva,Val,Leu,Phe,Pro,D,L-p-Cl- Phe,D-Pgly)是I-677单体摩尔活性的40～770倍,是FMDP的60～1130倍,其摩尔最低抑菌浓度为6.56×10^-9～3.5×10^-10mol·disk^-1。羧肽酶A存在时化合物I-677-FMDP体外抗菌试验表明,含FMDP的化合物I-677-FMDP能抵抗羧肽酶A的酶解。     

丁基苯酞对蛛网膜下腔出血后脑血流的改善及血脑屏障的保护作用

侧脑室注入自体血液造成蛛网膜下腔出血模型,观察丁基苯酞(dl-NBP)对局部脑血流的改善作用及血脑屏障的保护作用。结果表明,dl-NBP5～20mg·kg^-1明显提高蛛网膜下腔出血后3h内尾状核的血流量,但无明显的剂量效应关系。0.25mg·kg^-1的尼莫地平亦明显提高脑血流。并发现dl-NBP10mg·kg^-1及尼莫地平0.25mg·kg^-1(分别于蛛网膜下腔出血后5min和3hip)均能明显降低蛛网膜下腔出血6h后皮层组织中伊文氏蓝的摄取量,提示对血脑屏障有明显的保护作用。     

Influence of nitric oxide on morphine-induced conditioned place preference in the rat central amygdala

Effects of intra-central amygdala injections of L-arginine, a nitric oxide (NO) precursor, and N(G)-nitro-L-arginine methyl ester (L-NAME), a NO synthase (NOS) inhibitor, on morphine-induced conditioned place preference in rats were investigated by using an unbiased 3-day schedule of place conditioning design. Animals receiving once daily injections of morphine (0.5-7.5 mg/kg, subcutaneously, s.c.) or saline (1.0 ml/kg, s.c.) showed a significant place preference in a dose-dependent manner. The maximum response was observed with 5.0 mg/kg of the opioid. Co-administration of morphine (5.0 mg/kg) with L-arginine (0.3, 1.0 and 3.0 microg/rat), but not with L-NAME (0.3, 1.0 and 3.0 microg/rat), during the acquisition of morphine-induced conditioned place preference increased morphine-induced conditioned place preference. The response to L-arginine was blocked by L-NAME preadministration. L-arginine and L-NAME by themselves did not induce conditioned place preference. When L-arginine or L-NAME at 0.3-3.0 microg/rat was administered 1 min before conditioned place preference testing, L-arginine but not L-NAME caused an increase in the expression of morphine-induced conditioned place preference, the effect that was blocked by L-NAME preadministration. A dose of L-arginine (0.3 microg/rat), but not L-NAME, during expression of morphine-induced conditioned place preference produced an increase in locomotion compared with that in the control group. It may be concluded that an increase in the NO levels in the central amygdala may have an effect on the acquisition and expression of morphine-induced conditioned place preference.     

Constitutive nitric oxide modulates the injurious actions of vasopressin on rat intestinal microcirculation in acute endotoxaemia

The administration of the nitric oxide (NO) synthase inhibitor, N^G-nitro-l-arginine methyl ester (L-NAME, 5 mg/kg s.c.) concurrently with Escherichia coli endotoxin (3 mg/kg i.v.) increased vascular permeability and caused mucosal damage in the rat intestine 1 h later. The vasopressin V₁ receptor antagonist, [Mca¹,Tyr(Me)²,Arg⁸]vasopressin (0.01–0.2 μg/kg s.c., 15 min before endotoxin) dose-dependently reduced this damage. These results suggest a beneficial role of NO, counteracting the injurious vascular actions of endogenous vasopressin, in maintaining intestinal mucosal integrity in acute endotoxaemic states.     

丁基苯酞对原代培养的大鼠皮层神经细胞外液6-keto-PGF1α和TXB2及其比值的影响

目的旨在观察丁基苯酞(NBP)对神经细胞培养液中6-酮-PGF_1α和TXB₂含量及其比值的影响。用放射免疫方法,结果发现神经细胞在低糖低氧5h或低糖低氧5h/恢复糖氧3h条件下,d-,l-和dl-NBP(0.1～100μmol·L^-1)能够剂量依赖性升高细胞外液中的6-酮-PGF_1α含量,降低TXB₂水平,从而使6-酮-PGF_1α与TXB₂比值升高。而阿司匹林仅在小剂量(0.1,1μmol·L^-1)时能升高6-酮 PGF^1α与TXB^{2比值,大剂量(10,100μmol·L-1)时无影响。提示:NBP对6-酮-PGF_1α/TXB₂比值的升高可能与其增加局部脑血流和改善缺血性脑损伤有关。}     

丁基苯酞对局灶型脑缺血再灌大鼠脑hsp70mRNA和c-fos时相表达的影响

用原位杂交法和Northern印迹法,研究NBP对暂时性大脑中动脉阻断大鼠不同再灌期脑内hsp70mRNA和c-fos的时相表达的影响。发现缺血后再灌1h,在缺血侧有较明显的hsp70mRNA表达。再灌3h,6h和12h,表达逐渐加强。在缺血前10min和再灌即刻ipNBP10mg·kg^-1和20mg·kg^-1均能明显降低再灌6h和12hhsp70mRNA的表达。c-fos基因在再灌0.5h在缺血侧有清晰表达,再灌3h达峰值,再灌6h表达降低。ipNBP10mg·kg^-1(缺血前10min)可明显降低再灌1h和3h时c-fos的表达。Northern印迹法显示了同样的结果。提示NBP降低基因表达的作用可能是通过减轻缺血再灌引起的组织损伤来实现的。