伏隔核胆碱能神经元在线索诱导的海洛因复吸中的作用

目的 比较不同的二醋吗啡(海洛因)戒断时间对于环境线索(CC)或条件性线索(CS)诱导的大鼠复吸行为的影响,并探讨伏隔核胆碱能神经元可能的调节作用。方法 SD大鼠进行海洛因自身给药训练,每天4 h, 连续14 d,建立海洛因自身给药模型。随后置饲养笼自然戒断,随机分为第1天CC(d 1CC)组、d 14 CC组、d 1 CC+CS组和d 14 CC+CS组。测定有效鼻触次数,免疫组化双标法检测伏隔核(NAc)壳部和NAc核部胆碱乙酰转移酶(ChAT)与c-Fos共表达的水平。结果 海洛因自身给药大鼠随着戒断时间延长,CC诱导的海洛因觅药行为的恢复,即d 14 CC组与d 1 CC组比较,有效鼻触数明显增加(P<0.05);海洛因自身给药大鼠相同时间戒断后,不同线索诱导的海洛因觅药行为的恢复,即d 1 CC+CS组与d 1 CC组比较,以及d 14 CC+CS组与d 14 CC组比较,有效鼻触数均明显增加(P<0.05)。同时,在NAc壳部,与d 1 CC组比较,d 14 CC组大鼠的ChAT, c-Fos, ChAT+c-Fos免疫阳性细胞数分别为114±9,15±6,(13±5)个,ChAT+c-Fos占ChAT百分比为(11±4)%,明显增加(P<0.05);在NAc壳部和NAc核部,与d 1 CC组比较,d 1 CC+CS组大鼠的上述表达没有差异;在NAc壳部和NAc核部,与d 14 CC组比较,d 14 CC+CS组的ChAT, ChAT+c-Fos免疫阳性细胞数均明显减少(P<0.05)。结论 随着戒断时间的延长,CC诱导的海洛因觅药行为的增加,可能与NAc壳部胆碱能神经元的激活增多有关;而CS诱导的海洛因觅药行为的增加,可能与NAc壳部和核部胆碱能神经元的激活减少有关。     

高效液相色谱法测定吡美拉唑血药浓度及其药代动力学

目的 建立测定吡美拉唑血药浓度的高效液相色谱(HPLC)方法,并初步考察其在人体内的药代动力学特性。方法 受试者口服吡美拉唑10 mg后,分别于给药前,给药后0.5, 1, 1.5, 2, 4, 8, 12, 21, 36, 48, 60和72 h采集血样,通过HPLC吡美拉唑的血药浓度,并应用3P87软件拟合并计算药代动力学参数。结果 吡美拉唑的线性范围为25~4000 μg·L^-1,最低检测浓度为25 μg·L^-1,回收率95.2%~107.7%,日内精密度均<6.9%,日间精密度<10.2%。吡美拉唑的主要药代动力学参数:t_1/2为(22.58±1.59)h, AUC_0-72为(29 089±8886)μg·h·L^-1, Cl/F为(338.9±114.0)L·h^-1, t_max为(2.67±1.54)h, c_max为(1585±469)μg·L^-1。结论 吡美拉唑在人体内吸收快,半衰期较长,有效作用时间长,疗效好。     

丙泊酚对全脑缺血大鼠海马CA1区神经病理学和谷氨酸转运体1表达的影响

目的 观察丙泊酚对全脑缺血大鼠海马CA1区谷氨酸转运体1(GLT-1)表达的影响。方法 采用四血管闭塞法建立全脑缺血模型;脑缺血前3 h静脉输注丙泊酚90 mg·kg^-1,首次剂量(总剂量的1/3)15 min内推注,剩余剂量持续输注1 h。脑缺血再灌注后于0, 12, 24, 48 h和7 d取材。光镜下观察海马CA1区的组织学分级和神经元密度, Western印迹法检测海马CA1区GLT-1的表达。结果 组织学分级结果显示,假手术组及丙泊酚对照组所有动物均为0级,脑缺血模型组有5只动物均为Ⅲ级。丙泊酚+脑缺血组中3只动物的组织学分级为0级,2只动物为Ⅰ级。假手术组及丙泊酚对照组神经元密度分别为185±12及(181±11 )mm^-1。模型组中锥体细胞几乎全部死亡。与脑缺血组相比,丙泊酚+脑缺血组神经元密度为(125±14)mm^-1,说明存活细胞数显著增高(P<0.05)。Western印迹结果显示,与同一时间点的假手术组相比, 脑缺血后12 h,GLT-1的表达显著增强(0.31±0.03 vs 0.38±0.04), 随后逐渐降低,在脑缺血后7 d显著低于假手术组(0.19±0.03 vs 0.29±0.04)。丙泊酚对照组GLT-1的表达保持在较高的水平(0.47±0.05),直到7 d才降至假手术组水平0.29±0.03。在再灌注后24和48 h时,丙泊酚明显逆转脑缺血造成的GLT-1表达的下降, GLT-1表达分别为0.45±0.04 vs 0.29±0.04和0.47±0.05 vs 0.27±0.04(P<0.05),在7 d时与假手术组相当。结论 丙泊酚可保护海马CA1区的锥体细胞抵御缺血打击,并上调了大鼠海马CA1区GLT-1的表达。     

多西他赛治疗非小细胞肺癌的时辰药理学研究

目的 比较多西他赛在不同时间点给药后的血药浓度、疗效以及毒性反应的变化,根据其节律变化选择临床最佳给药时间,获得最佳疗效。方法 经病理和细胞学证实的60例III、IV期非小细胞肺癌(NSCLC)患者随机分为3组。多西他赛：A组(n=20)在8∶00 am给药,B组(n=20)在2∶00 pm给药,C组(n=20)在8∶00 pm给药;顺铂在多西他赛给药后第2天给予。多西他赛40 mg·m^-2,ivgtt,d1,8;顺铂75 mg·m^-2,ivgtt,d1,第21天重复。测定给药后1,10,24 h的血药浓度,并评价经化疗2个周期后的疗效和不良反应。结果 3组的疗效和血药浓度在统计学上没有显著性差异,但2:00 pm,8:00 pm给药组的不良反应发生率较高。结论 多西他赛治疗NSCLC在8∶00 am给药较为安全有效,可增加病例数做进一步的深入研究。     

大鼠甲基苯丙胺自身给药行为模型构建

目的獉獉:建立大鼠甲基苯丙胺自身给药行为模型。方法獉獉:训练♂SD大鼠通过鼻触行为进行甲基苯丙胺静脉自身给药,训练期剂量0.03 mg.kg-1或0.06 mg.kg-1。每天进行4 h。固定频率(FR)和渐变频率(PR)测试剂量为0.015、0.03、0.06、0.09和0.12 mg.kg-1)FR和PR测试分别为4 h和6 h。戒断停药2周后,大鼠重新返回实验笼进行消退及复吸测试,包括6个阶段的消退和一个阶段的复吸测试。结果獉獉:训练7 d后,80%的实验大鼠建立稳定的甲基苯丙胺静脉自身给药行为。FR剂量效应曲线是一条下降的曲线,即随着剂量的增加实验大鼠鼻触数降低。PR曲线是一条上升的曲线,即随着剂量的增加实验大鼠断点数逐渐增加。消退和复吸测试中主要测试有效鼻触数。经过6个阶段的消退测试,实验大鼠有效鼻触数下降到3±s 3次。随后经过一个阶段的复吸测试,大鼠有效鼻触数可上升至57±s 8次。结论獉獉:通过自身给药训练实验大鼠成功的获得了甲基苯丙胺的自身给药行为,消退和相关环境线索诱导的复吸模型。     

吡格列酮对脂多糖诱导星形胶质细胞诱导型一氧化氮合酶表达的抑制作用

目的 研究吡格列酮(Pio)对脂多糖 (LPS) 诱导星形胶质细胞(AC)诱导型一氧化氮合酶(iNOS)的抑制作用及其作用机制。方法 AC分别加入Pio 0.1, 1.0和10.0 μmol·L^-1, c-Jun氨基端激酶(JNK)抑制剂SP600125 20.0 μmol·L^-1, p38丝裂原活化蛋白激酶(p38MAPK)抑制剂SB203580 20.0 μmol·L^-1或过氧化物酶体增殖物激活受体γ(PPARγ)抑制剂GW9662 10.0 μmol·L^-1,1 h以后加入LPS 10.0 mg·L^-1, 继续作用24 h。Griess法测定培养AC上清液中一氧化氮(NO)含量。免疫印迹法和免疫荧光法检测iNOS的表达水平。结果 与正常对照组相比,LPS 10.0 mg·L^-1组iNOS表达水平和NO分泌水平均显著增高(P<0.01)。Pio 0.1, 1.0和10.0 μmol·L^-1可明显抑制LPS诱导的iNOS表达上调及NO分泌增加(P<0.05),Pio 10.0 μmol·L^-1组iNOS蛋白表达水平由LPS组1.711±0.283下降到0.157±0.082(P<0.01),NO分泌量由LPS组(16.63±2.25)μmol·L^-1下降到(6.92±1.30)μmol·L^-1(P<0.01)。GW9662 10.0 μmol·L^-1可抑制Pio 1.0 μmol·L^-1的上述作用,iNOS蛋白表达水平由Pio 1.0 μmol·L^-1组0.562±0.100增加到0.847±0.088(P<0.01),NO分泌量由(9.27±1.23)μmol·L^-1增加到(15.54±2.30)μmol·L^-1(P<0.01)。SB203580 20.0 μmol·L^-1和SP600125 20.0 μmol·L^-1的作用与Pio作用相似,使iNOS蛋白表达水平降低到0.434±0.082和0.434±0.076,NO分泌量下降到(11.53±2.40)μmol·L^-1和(8.81±0.58)μmol·L^-1;而单独应用SB203580 20.0 μmol·L^-1和SP600125 20.0 μmol·L^-1对AC的iNOS表达和NO分泌没有影响。结论 Pio能通过抑制LPS诱导的大鼠皮质AC的iNOS表达,从而减少NO的分泌,这种抑制作用可能与其激活PPARγ和阻断JNK和p38MARK信号转导通路有关。     

不同发育期大鼠海马N-甲基-D-天冬氨酸受体3A亚基的表达及其抗缺血缺氧能力

目的 观察不同发育时期海马神经元N-甲基-D-天冬氨酸(NMDA)受体3A亚基(NR3A)的表达及其抗缺血缺氧能力与其NR3A表达量的关系。方法 取鼠龄1, 5, 10, 15, 20, 30和90 d大鼠海马,采用Western印迹法检测海马神经元NR3A表达;制备鼠龄10, 15, 20和30 d大鼠海马切片,免疫组化法检测NR3A表达。取鼠龄10, 15, 20和30 d海马脑片,体外制备氧糖剥夺损伤模型(OGD),采用PI染料标记和荧光方法检测观察神经元坏死情况。结果 Western印迹和免疫组化结果显示,大鼠海马NR3A亚基的表达以10 d鼠龄时最高,此后逐渐下降,直至成年都一直维持较低的水平。对海马脑片进行OGD处理后,鼠龄10 d的海马脑片受损细胞数明显少于其他组,5 d,20 d组PI阳性细胞数多于10 d,鼠龄30 d的海马脑片损伤细胞数最多。结论 鼠出生后海马神经元NR3A亚基表达呈现先高后低的状态,成年鼠NR3A亚基的表达量维持在较低水平。NR3A亚基的高表达有利于神经元对抗OGD造成的损伤。     

γ-氨基丁酸能去抑制对脊髓细胞外信号调节激酶2的激动作用

目的 探讨脊髓γ-氨基丁酸(GABA)能去抑制对细胞外信号调节激酶1/2(ERK1/2)活性的影响及其与痛行为改变的关系。方法 正常小鼠鞘内注射(ith)比扣扣灵碱(荷包牡丹碱, bicuculline)50 ng·g^-1(5 μl)模拟GABA能去抑制,左后足底sc给予弗氏完全佐剂制备炎性疼痛模型,小鼠ith给予GABA_A受体激动剂地西泮0.5 μg·g^-1(5 μl)或ERK1/2抑制剂PD-98059 0.25 μg·g^-1(5 μl)后,测定ERK1/2活性和小鼠缩足阈值。结果 与正常对照组的缩足阈值(1.24±0.07)g相比, 正常小鼠ith给予比扣扣灵碱50 ng·g^-1的缩足阈值显著降低((0.42±0.17)g,P<0.05),给予PD-98059 0.25 μg·g^-1后缩足阈值显著升高((1.29±0.37)g,P<0.05)。与炎性疼痛模型组的缩足阈值(0.28±0.06)g相比,炎症小鼠ith给予地西泮0.5 μg·g^-1的缩足阈值显著升高((0.99±0.12)g,P<0.05),且给予PD-98059 0.25 μg·g^-1后缩足阈值也显著升高((0.97±0.17)g,P<0.05)。Western免疫印迹结果显示,与正常对照组相比,比扣扣灵碱显著提高ERK2的磷酸化水平((152±24)%,P<0.05)。并且弗氏完全佐剂也可提高小鼠脊髓ERK2的磷酸化水平((163±42)%,P<0.05),ith给予地西泮0.5 μg·g^-1,则显著降低CFA诱发的小鼠脊髓ERK2的磷酸化水平((91±34)%,P<0.05),同时地西泮和PD-98059有效缓解炎性疼痛症状。结论 GABA能去抑制对脊髓背角ERK2有激活作用,并与炎性疼痛的形成有关。     

水胺硫磷在大鼠肝微粒体的生物转化和代谢动力学

目的 探讨水胺硫磷在大鼠肝微粒体的体外代谢活化产物及代谢动力学特征。方法 应用液相色谱-四级杆-飞行时间质谱(LC/QTOF MS)筛查并鉴定水胺硫磷在大鼠肝微粒体孵育液中的氧化产物。用乙酰胆碱酯酶抑制法考察水胺硫磷及其氧化产物水胺氧磷的抑酶活性。应用液相色谱-三重四级杆串联质谱(LC/Triple-Q MS/MS)定量检测肝微粒体中的水胺硫磷及其代谢产物水胺氧磷,研究水胺硫磷及其产物的消长动力学和氧化产物生成的酶动力学。结果 筛查并鉴定了水胺硫磷在大鼠肝微粒体的氧化脱硫产物水胺氧磷。水胺氧磷对乙酰胆碱酯酶的抑制活性远高于水胺硫磷,IC₅₀值比水胺硫磷低4个数量级,表明水胺硫磷的氧化脱硫反应是一个代谢活化过程。水胺硫磷在大鼠肝微粒体中的半衰期(t_1/2)为14.6 min,外推得到体内肝清除率Cl_H为43.8 ml·min^-1·kg^-1。水胺氧磷的生成符合双相酶动力学模型,K_m,app1为1.12 μmol·L^-1,产物生产最大速率(V_max1)为0.43 μmol·min^-1·g ^-1;蛋白K_m,app2为67.92 μmol·L^-1,V_max2为1.28 μmol·min^-1·g ^-1蛋白。结论 水胺硫磷在大鼠肝微粒体中能快速代谢消除,生成抑酶活性更高的产物水胺氧磷而产生毒性。     

复方苯磺酸氨氯地平/盐酸贝那普利片人体药动学研究

目的 研究健康受试者单剂量与多剂量口服复方苯磺酸氨氯地平/盐酸贝那普利片后的药动学。 方法 LC-MS/MS测定单剂量与多剂量给药后氨氯地平与贝那普利及贝那普利拉血药浓度并利用DAS软件计算药动学参数。结果 单剂量给药氨氯地平与贝那普利及贝那普利拉的主要药动学参数分别是：t_1/2为(47.3±10.6),(1.3±0.4)和(4.5±0.6) h,C_max为(6.4±1.5),(136.5±40.2)和(158.3±46.7)μg·L^-1,AUC_0-t为(267.7±88.4),(144.3±46.7)和(891.4±265.4)μg·h·L^-1;多剂量给药氨氯地平与贝那普利的主要药动学参数分别是：t_1/2为(45.1±8.7),(1.4±0.4)和(5.3±0.8)h,C_max为(8.2±1.8),(142.4±47.5)和(165.2±40.8)μg·L^-1,AUC_0-t为(413.5±102.4),(155.7±52.8)和(915.7±316.9)μg·h·L^-1,R为(1.6±0.6)、(1.0±0.1)和(1.2±0.1)。结论 复方苯磺酸氨氯地平/盐酸贝那普利片2组分及活性代谢产物在健康受试者体内的吸收速率和消除速度不随连续给药变化,但连续给药后苯磺酸氨氯地平在体内有轻微蓄积。     

Prenatal lead exposure enhances methamphetamine sensitization in rats

Adult female rats were exposed to lead-free sodium acetate via gavage [0 mg (vehicle control)] or to 16 mg lead as lead acetate for 30 days prior to breeding. Following confirmation of breeding, the female animals continued to be exposed to their respective doses throughout gestation and lactation. When weaned, 16 control and 16 lead-exposed offspring were placed on regular water and food (lead-exposure was discontinued) until postnatal day (PND) 70. At this time, one-half of the control animals and one-half of the lead-treatment animals received intraperitoneal (i.p.) injections of the vehicle (saline) for 10 successive days and the remaining animals in each exposure conditions received daily injections of 1.0 mg/kg (+)-methamphetamine (METH) for 10 days (N = 8/group). Locomotion in automated chambers was monitored daily for 45 min post-injection.Subsequently, during dose-effect testing, all animals received consecutive daily i.p. injections of 0, 1.0, 2.0, and then 4.0 mg/kg METH. The results of the experiment showed that both control and lead-exposed animals exhibited heightened locomotor activity (i.e. behavioral sensitization) to the repeated administration of 1.0 mg/kg METH. More importantly, animals developmentally (perinatally) exposed to lead showed more rapid sensitization than did their control counterparts. These data indicate that early lead exposure increases sensitivity to the locomotor-stimulating effects of METH. In contrast, identically exposed lead animals exhibit diminished METH dose-effect responding when tested in an intravenous (i.v.) self-administration paradigm [Rocha A., Valles R., Bratton G.R., Nation J.R. Developmental lead exposure alters methamphetamine self-administration in the male rat: acquisition and reinstatement. Drug Alcohol Depend 2008a;95:23-29, Rocha A., Valles R., Hart N., Bratton G.R., Nation J.R. Developmental lead exposure attenuates methamphetamine dose-effect self-administration performance and progressive ratio responding in the male rat. Pharmacol Biochem Behav 2008b;89:508-514].     

幼年注射氟西汀诱导制备成年ICR小鼠抑郁模型

目的通过幼年注射氟西汀(Flu)制备成年小鼠抑郁模型,探讨其表观有效性和预测有效性。方法 幼年ICR小鼠出生后第4到第21天连续ip给予Flu 10 mg.kg-1(幼年诱导模型组),正常饲养至9周龄后,分为模型组、ig给予Flu 10 mg.kg-1和氟哌啶醇0.1 mg.kg-1组,连续3周后开始检测实验,测试期间继续给药,测试完成后小鼠为12～13周龄。开场实验检测跨格数,悬尾实验检测不动时间,明暗穿箱实验检测明暗穿箱次数。结果 与正常对照组相比,幼年诱导模型组小鼠成年后,自主活动显著减少(跨格数:83±30 vs 58±19;站立数:32±10 vs 20±8),悬尾不动时间显著延长〔83±46 vs(128±56)s〕,明暗穿箱次数显著减少(18±5 vs 10±4)。小鼠连续ig给予Flu 10 mg.kg-1后,自主活动显著增加(跨格数:58±19 vs 85±41;站立数:20±8 vs 30±12),悬尾不动时间显著缩短〔128±56 vs(71±40)s〕,明暗穿箱次数显著增加(10±4 vs 17±7),各指标均恢复至正常对照组水平;而给予氟哌啶醇0.1 mg.kg-1组小鼠,各指标数据无明显改变,同时表现出镇静作用。结论 幼年小鼠注射Flu成年后的表现符合抑郁模型表观有效性和预测有效性特征,有望成为制备更合理的抑郁症动物模型方法。     

Circadian variations in the pharmacokinetics, tissue distribution and urinary excretion of nifedipine after a single oral administration to rats

Circadian variations in the pharmacokinetics, tissue distribution and urinary excretion of nifedipine were examined in fasted rats after administering a single oral dose at three different dosing times (08:00 am, 16:00 pm, 00:00 am). The plasma concentrations, the areas under the plasma concentration-time curve from zero to 6 h (AUC(0-6 h)) and the peak plasma concentration (C(max)) were significantly higher in the rats dosed at 08:00 am (immediately inactive), and was lower at 16:00 pm (most inactive) and 00:00 am (most active). The time to reach the C(max) (T(max)) was the shortest in the rats dosed at 08:00 am. It was very interesting to observe the double peak phenomena in the plasma concentration profiles, showing a larger peak followed by a smaller peak. There was a dosing time dependency on the tissue distribution 30 min after administration, showing a similar tendency to the pharmacokinetic behavior. However, there was no distinct dosing time dependency observed at 2 h after administration due to the extensive disposition. The cumulative urine excretion of nifedipine in the rats dosed at 08:00 am was significantly higher (about two-fold) than in those dosed at 16:00 pm and 00:00 am. The pharmacokinetics of nifedipine in the rats was consistent with that observed in human subjects in terms of the day-night clock time but the biological time was the opposite, as marked by the rest-activity cycles. These results may help to explain the circadian time-dependency of nifedipine pharmacokinetics.     

Intravenous methamphetamine self-administration in rats: effects of intravenous or intraperitoneal MDMA co-administration

The combined use of 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy') with methamphetamine (METH) by recreational drug users is of particular concern due to their similar pharmacological and toxic profiles. In the current study we sought to elucidate why combining these particular drugs is such a popular choice among party-drug users. This was investigated through characterisation of the possible interactive effects of MDMA on METH intravenous self-administration. The first experiment involved characterisation of the METH dose-response curve for intravenous self-administration. Male Hooded-Wistar rats were trained to self-administer intravenous METH (0.01-0.3 mg/kg/infusion) and an inverted-U dose-response curve was obtained. In Experiment 2, a second squad of rats self-administered 0.01, 0.03 or 0.1 mg/kg/infusion METH and had small amounts of MDMA (0.001-0.03 mg/kg) then introduced into the infusion solution. Addition of MDMA to the METH infusion solution resulted in a dose independent reduction in responding. In Experiment 3, a third squad of rats was treated 20 min pre-session with an intraperitoneal injection of saline, 1.25 or 2.5 mg/kg of MDMA or METH to evaluate whether the reduction in responding evident in Experiment 2 was due to an MDMA-induced decrease in locomotor activity. Pre-treatment with intraperitoneal MDMA or METH had no effect on METH self-administration nor activity. We hypothesise that the reduction in METH self-administration caused by MDMA may reflect inhibitory effects of MDMA-induced 5-HT release on dopaminergic mechanisms.     

Increases of CRF in the amygdala are responsible for reinstatement of methamphetamine-seeking behavior induced by footshock

Recent evidence suggests the involvement of corticotropin-releasing factor (CRF) in drug abuse. Here, we evaluated whether CRF modulates the reinstatement of methamphetamine (METH)-seeking behavior induced by stress using a drug-self administration paradigm in rats. Rats were trained to lever-press for intravenous METH (0.02 mg/infusion) accompanied by light and tone (drug-associated cues) and then underwent extinction training (saline substituted for METH without cues). Under the extinction condition, the inhibitory effects of a CRF receptor antagonist on the stress-induced reinstatement of METH-seeking behavior were assessed. Anxiety-like behaviors during METH withdrawal in METH self-administered rats were also evaluated. The non-selective CRF receptor antagonist α-helical CRF_9-41 attenuated METH-seeking behavior induced by footshock stress. CRF levels both in the amygdala and in plasma were significantly increased on day 10 of withdrawal after METH self-administration. However, plasma corticosterone concentrations were unchanged during the withdrawal. In addition, METH-seeking behavior was not affected by an inhibitor of corticosterone synthesis, metyrapone. In the elevated plus maze test, METH self-administered rats showed a decrease in the duration of time spent in the open arms on day 10 of withdrawal. The increased CRF levels in the amygdala may, at least in part, contribute to the footshock-induced reinstatement of METH-seeking behavior and the increase in anxiety-like behavior. The present findings indicate that CRF receptor antagonists would be useful as a therapeutic agent for METH-dependence.     

缬沙坦联合川芎嗪对血管性痴呆模型大鼠空间学习记忆能力的影响

目的比较缬沙坦和川芎嗪单独及联合应用对血管性痴呆(VD)模型大鼠空间学习记忆能力的影响,并探讨其可能的作用机制。方法大鼠ip给予硝普钠2.5mg·kg-1后,夹闭双侧颈总动脉缺血10min,再灌注10min,重复2次,制备VD大鼠模型。VD模型制备后24h,治疗组大鼠于每天上午9:00ig给予缬沙坦8mg·kg-1,川芎嗪25mg·kg-1或缬沙坦+川芎嗪(8+25mg·kg-1),每天1次,连续15d,同时设假手术和模型组。Morris水迷宫检测大鼠空间学习记忆能力;Morris水迷宫实验结束后第2天取海马,逆转录PCR检测海马组织白细胞介素1β(IL-1β)mRNA表达;免疫组织化学法检测海马肿瘤坏死因子α(TNF-α),Bcl-2和Bax蛋白表达。结果末次给药后连续5d进行大鼠定位航行训练,训练的第3,4和第5天,模型组大鼠逃避潜伏期分别为43±19,22±10和(16±7)s,与假手术组32±15,16±8和(10±6)s比较明显延长(P<0.05);第6天,模型组大鼠在平台象限停留时间为(35.3±10.0)s,跨越虚拟平台(3.4±1.7)次,平台象限游程百分比为(30±6)%,与假手术组(6.3±2.5)s,(51±11)次和(38±8)%比较明显降低(P<0.05);模型组大鼠海马组织IL-1βmRNA和海马CA1区TNF-α,Bcl-2和Bax蛋白表达与假手术组比较明显增加(P<0.05)。与模型组比较,第4和第5天,缬沙坦、川芎嗪单用和联合应用组大鼠逃避潜伏期明显缩短,分别为18±9和(13±7)s,18±9和(14±7)s及17±8和(11±7)s(P<0.05,P<0.01);联用组大鼠跨越平台的次数、在平台象限停留的时间及平台象限游程百分比均明显增加,分别为(5.6±1.9)次,(50±8)s和(37±6)%(P<0.05),缬沙坦和川芎嗪单用组上述指标改变不明显;二者联用组海马IL-1βmRNA,TNF-α和Bax蛋白表达均明显降低,Bcl-2蛋白表达明显增强(P<0.01);缬沙坦和川芎嗪单用组海马CA1区Bcl-2蛋白表达增强,Bax蛋白表达降低(P<0.01),海马组织IL-1βmRNA表达无明显变化;缬沙坦组海马CA1区TNF-α蛋白表达减少(P<0.05);川芎嗪组TNF-α蛋白表达无明显改变。结论缬沙坦及川芎嗪可改善VD大鼠学习记忆功能,二者联用作用更加明显。该作用可能与其抑制炎症反应及抑制海马神经元凋亡有关。     

Repeated self-administered cocaine "binges" in rats: effects on cocaine intake and withdrawal

RATIONALE: Repeated access to cocaine may engender behavioral sensitization, which emerges as an enhanced response to the effects of cocaine. Repeated exposure to prolonged self-administration sessions has been shown to produce an escalation in cocaine intake. OBJECTIVE: The objective of the present study was to identify the consequence of repeated exposure to prolonged access to self-administered cocaine. METHODS: Pairs of rats that were matched for training, housing, and surgery were treated as a single experimental unit, and these pairs were separated into groups for two separate experiments. In the first experiment, one animal of the pair acquired and maintained a stable rate for i.v. cocaine self-administration (0.5 mg/infusion), while the second rat was yoked such that it passively received saline infusions in the same pattern. After acquisition, the active self-administration rats were given free access to cocaine for 16 h (binge), while the yoked animal continued to receive infusions of saline. Twenty-four hours after the binge, both animals were exposed to tactile startle stimuli, and ultrasonic vocalizations (USVs) and startle reflexes were measured. The animals were exposed to three cocaine binges and 24 h post-binge startle tests with an interval of 10 days between binges, and then a fourth binge, with an interval of 24 h separating binges three and four. In the second experiment, pairs of rats were separated into three groups (A, B, and C). The active cocaine rats acquired self-administration and were allowed access to a 16-h cocaine binge while their yoked controls received saline. Twenty-four hours after the binge, all animals were tested for emission of USVs and startle reflexes with an identical protocol as that in experiment 1. Immediately after exposure to the startle stimuli, the self-administering animals were again allowed to self-administer cocaine for either 16 (group A), 12 (group B), or 8 h (group C). RESULTS: In experiment 1, the total amount of cocaine self-administered was significantly decreased when the cocaine binges were separated by 10 days, but total cocaine intake during the binge significantly increased when the drug-free interval was 24 h. The pattern of self-administration and the withdrawal response remained unchanged over consecutive binges. In experiment 2, rats that self-administered cocaine for either 16 or 12 h emitted significantly less USVs immediately after renewed access than they emitted 24 h after the first access period. CONCLUSION: It appeared that consecutive prolonged self-administration was insufficient to produce sensitization, as measured by cocaine intake and renewed access to self-administered cocaine was sufficient to reduce the large number of USVs that characterize withdrawal from a cocaine binge.     

黄芪配伍熟地对去势大鼠骨质疏松的治疗作用

目的观察黄芪配伍熟地对去势大鼠骨密度及骨质病理改变的影响。方法采用切除雌性未孕大鼠两侧卵巢的方法制备去势大鼠骨质疏松模型。模型大鼠按照分组分别ig给予黄芪5.4g·kg-1,熟地5.4g·kg-1,黄芪+熟地(含黄芪2.7g·kg-1和熟地2.7g·kg-1),雌激素0.18mg·kg-1,每2周1次连续给药16周。制作骨骼切片,检测去势大鼠骨密度及骨质病理的改变。结果与假手术组比较,模型组的体质量显著增加,股骨质量〔(1.05±0.11)g〕明显降低,骨量丧失较为明显(P<0.05)。与模型组比较,黄芪组〔(373±63)g〕、熟地组〔(370±46)g〕及黄芪+熟地组的体质量〔(370±60)g〕均明显增加(P<0.05),但股骨量无显著变化;黄芪+熟地组的股骨密度(0.1470±0.0373)g·cm-1和椎骨骨密度(0.1350±0.0402)g·cm-1均明显增加(P<0.05),骨皮质厚度(0.852±0.151)g·cm-1及骨小梁直径(0.073±0.015)g·cm-1显著性增加(P<0.05)。结论黄芪配伍熟地能够增加骨密度、促进骨形成,使骨结构得到改善,对去卵巢大鼠骨质疏松具有一定的治疗作用。     

Exploratory studies in sensory reinforcement in male rats: effects of methamphetamine

Understanding sensory reinforcement and the effects of stimulant drugs on sensory reinforcers is potentially important for understanding their influence on addiction processes. Experiment 1 explored the reinforcing properties of a visual stimulus and the effects of methamphetamine (METH) on responding maintained by a visual reinforcer (VRF) in male rats. Snout poke responses to the active alternative produced the VRF according to variable interval (VI) schedules of reinforcement, and responses to an inactive alternative had no programmed effect. Experiment 2 explored the effects of METH on choice between the VRF and a water reinforcer (H2ORF) using concurrent VI schedules in male rats. In Experiment 1, response-contingent onset of the VRF produced an increase in both the relative frequency and absolute rate of active responding. The rate of both active and inactive responding declined across the 40-min test sessions. METH did not differentially enhance active responding for the VRF. Instead, METH nondifferentially increased the rate of responding and attenuated the within-session decline of responding. In Experiment 2, METH differentially increased the rate of responding for the VRF relative to the H2ORF. The results of these exploratory experiments indicate that the reinforcing effects of the VRF were weak and transient. In addition, METH treatment increased responding, and the specificity of the enhancement of METH was dependent upon the testing conditions. Potential explanations of these differences, such as novelty and reinforcer type, are discussed.