镧对大鼠海马CA1区环磷酸腺苷应答元件结合蛋白磷酸化的影响

目的探讨镧的神经毒性作用机制。方法 40只Wistar孕大鼠通过自由饮水的方式随机分为正常对照组,LaCl30.25%,0.5%和1.0%染毒组。染毒组仔鼠在断乳前通过母乳染毒,断乳后通过自由饮水的方式染毒1个月。电感耦合等离子体质谱法检测海马CA1区镧含量;磷酸二酯酶法检测海马CA1区钙调蛋白(CaM)活性;Western印迹法检测磷酸化钙调蛋白依赖性蛋白激酶Ⅳ(p-CaMKⅣ),磷酸化环磷酸腺苷应答元件结合蛋白(p-CREB)和c-jun蛋白表达;RT-PCR法检测c-jun mRNA表达水平。结果与正常对照组相比,LaCl30.25%,0.5%和1.0%染毒组海马CA1区镧含量显著高于正常对照组,分别为正常对照组的7.3,12.0和20.0倍(P<0.05);海马CA1区CaM活性显著降低,分别为正常对照组的80.7%,59.9%和30.6%(P<0.05);海马CA1区p-CaMKⅣ表达降低,分别为正常对照组的83.0%,57.4%和27.7%(P<0.05),p-CREB表达显著降低,分别降低了24.4%,36.6%和73.2%(P<0.05),c-jun蛋白表达显著降低,分别降低了36.1%,45.9%和83.6%(P<0.05),c-jun mRNA表达显著降低,分别降低了14.8%,27.2%和76.5%(P<0.05)。结论镧可能与钙竞争结合于CaM,造成海马CA1区CaM活性和CaMKⅣ,CREB磷酸化以及c-jun基因转录和蛋白表达水平下降,从而损害大鼠的学习记忆能力。     

缓激肽诱导胶质瘤细胞内cAMP反应元件结合蛋白磷酸化的实验研究

目的观察缓激肽作用下,大鼠C6胶质瘤细胞中转录因子cAMP反应元件结合蛋白(cAMP response element bind-ing protein,CREB)磷酸化的动态变化,并探讨其可能的意义。方法应用免疫细胞化学和Western blot方法,观察1μmol.L-1缓激肽作用C6胶质瘤细胞在不同时相点(0,5,10,15,20,30min)CREB磷酸化的动态变化。结果1μmol.L-1缓激肽作用C6胶质瘤细胞的5到30min的各时相点均能检测到CREB的磷酸化(P<0.01),其中以15min的磷酸化最强(P<0.01)。结论缓激肽可促进大鼠C6胶质瘤细胞中转录因子CREB的磷酸化,此作用可能与其促进血肿瘤屏障的选择性开放有关。     

加味四逆散对皮质酮和谷氨酸致损伤的PC12细胞中cAMP反应元件结合蛋白及其磷酸化的影响

目的研究中药复方加味四逆散(JWSNS)对皮质酮和谷氨酸致损伤的PC12细胞中cAMP反应元件结合蛋白(CREB)及其磷酸化的影响。方法以200μmol.L-1Cort和50μmol.L-1Glu损伤的PC12细胞作为体外药理学研究模型,制备JWSNS含药血清,采用免疫组织化学法和West-ernblot法检测PC12细胞损伤模型中CREB和磷酸化CREB蛋白的表达。结果200μmol.L-1Cort和50μmol.L-1Glu可导致PC12细胞中CREB和p-CREB表达下降(CREB阳性细胞率分别为17.1%±4.2%和20.8%±5.7%,p-CREB表达量分别为0.587±0.123和0.515±0.157,P<0.05或P<0.01),10%JWSNS含药血清能升高CREB和p-CREB的表达(CREB阳性细胞率分别为62.6%±11.7%和79.5%±7.6%,p-CREB表达量分别为1.298±0.112和1.269±0.128,P<0.05或P<0.01)。结论10%JWSNS含药血清能通过调节cAMP-CREB信号通路发挥其神经保护和抗抑郁的作用。     

cAMP反应元件结合蛋白在药物依赖形成中的作用

反复应用成瘾性药物引起中枢神经系统特定部位cAMP信号系统出现适应性改变 ,cAMP反应元件结合蛋白(cyclicAMPresponseelementbindingprotein ,CREB)是受cAMP调节的主要转录因子 ,在动物产生药物依赖时脑内CREB含量及磷酸化程度发生变化 ,与动物躯体依赖和精神依赖有关。确定CERB在药物依赖中的作用有益于阐明药物依赖分子机制及采取相应的防治措施     

酒精依赖大鼠皮质CREB变化及氟西汀对其影响

目的　研究酒依赖大鼠皮质cAMP反应元件结合蛋白 (CREB)、磷酸化CREB( p CREB)蛋白表达的变化 ,并观察氟西汀对其影响。方法　给大鼠自由饮含低浓度乙醇 (体积分数为 6% )的水溶液 2 8d。采用免疫组织化学方法检测大鼠皮质CREB、p CREB蛋白表达。结果　撤除酒精后大鼠前额皮质、梨状皮质的p CREB蛋白表达均降低 ,其中以戒断 2 4h时降低最明显 ,与对照组比较两部位分别降低5 7 2 8%、5 5 84%。氟西汀 ( 10mg·kg-1,ip)能减轻饮酒大鼠戒断症状 ,增加大鼠戒断 2 4h时前额皮质、梨状皮质 p CREB水平 ,与饮酒组戒断 2 4h比较两部位分别增加2 92 5 8%、12 8 44 %。结论　CREB可能是介导酒精依赖的受体后信号转导物质之一 ,氟西汀对酒精戒断症状的改善与其拮抗酒精戒断诱导的 p CREB降低有关     

Sex differences in muscarinic receptor binding after chronic ethanol administration in the rat

Male and female rats were administered ethanol (5% v/v) in a liquid diet for 18 weeks. Pair-fed control animals were fed the same diet except that dextrose was substituted isocalorically for ethanol. Normal controls received a commercial laboratory chow for the same duration. Results showed that, in females, chronic ingestion of an ethanol liquid diet significantly increased the number of muscarinic receptor binding sites compared to both control groups. In contrast, for males, there was no significant difference in the mean number of binding sites among the treatment groups. Furthermore, the mean maximum number of binding sites for males and females varied across brain areas. Males had a significantly greater number of receptor binding sites than females in the striatum, while females had a greater number in the cortex. It was suggested that the geuder differences observed in the present study could be mediated by hormonal effects on central muscarinic functioning.     

Changes in social behaviour of rats following chronic treatment with gamma-endorphin antiserum injected into the nucleus accumbens

Treatment with gamma-endorphin antiserum twice daily for 12 days, by injection into the nucleus accumbens did not change the basal level of social activity or explorative behaviour when pairs of rats were tested in a social interaction test. The decrease in social interactions due to increased light level as observed in placebo-treated rats, was not present in animals treated with gamma-endorphin antiserum. Significantly more freezing and fly-responses were observed in the rats treated with antiserum, as reactions to penetrating sound stimuli. These changed responses to light and sound stimuli persisted for at least 3 days following discontinuation of treatment. It is concluded that treatment with gamma-endorphin antiserum, injected into the nucleus accumbens results in disturbances in the integration of environmental stimuli in social behaviour and in enhanced responsiveness to stressful stimuli. It is suggested that these effects may be related to increased dopaminergic transmission in some dopaminergic systems in the nucleus accumbens, implicating these systems in the environmental control over social behaviour.     

Effects of ohmefentanyl stereoisomers on phosphorylation of cAMP-response element binding protein in cultured rat hippocampal neurons

AIM: To define the effects and signal pathways of ohmefentanyl stereoisomers [(-)-cis-(3R,4S,2'R) OMF (F9202), (+)-cis-(3R,4S,2'S) OMF (F9204), and (-)-cis-(3S,4S,2'R) OMF (F9203)] on the phosphorylation of cAMP-response element binding protein (CREB) in cultured rat hippocampal neurons. METHODS: The effects of the three OMF stereoisomers and morphine (Mor) on cAMP accumulation and CREB phosphorylation were monitored by radioimmunoassay and Western blot analysis, respectively. RESULTS: The three OMF stereoisomers and Mor could all partially inhibit forskolin-stimulated (25μmol/L, 15min) cAMP accumulation in a dose-dependent manner and this effect could be reversed by naloxone. F9202, F9204, and Mor could significantly increase CREB phosphorylation from 2.88 to 3.59 folds over control levels after 30-min exposure. This effect was reversed by naloxone, but F9203 failed to increase CREB phosphorylation. KN-62 and staurosporine significantly blocked the opioidsinduced CREB phosphorylation, while H-89 and P     

东莨菪碱对吗啡诱发条件位置性偏爱重现大鼠杏仁核p-CREB及c-Fos表达的影响

目的：探讨东莨菪碱对吗啡诱发条件位置性偏爱（conditioned place preference,CPP）重现大鼠杏仁核（amygdala nucleus,Amy）cAMP反应元件结合蛋白（phospho-cAMP response element binding protein,p-CREB）和c-Fos表达的变化。方法：以剂量递增法建立大鼠CPP模型,生理盐水替代吗啡训练大鼠,使形成的CPP逐渐消退,小剂量吗啡激活已消退的CPP。采用免疫组化技术测定不同剂量东莨菪碱对吗啡诱发CPP重现时大鼠杏仁核p-CREB和c-Fos的变化。结果：东莨菪碱可抑制吗啡点燃诱发大鼠CPP重现行为;并可减少吗啡诱发的CPP重现时大鼠杏仁核p-CREB和c-Fos的表达。结论：东莨菪碱对小剂量吗啡诱发吗啡依赖大鼠CPP重现行为的抑制作用可能与其抑制大鼠杏仁核p-CREB和c-Fos蛋白表达有关。     

Modulation of dopamine function by glycine in the nucleus accumbens of the brain of the rat

The effects of glycine on the phasic changes in locomotor activity in the rat, caused by a persistent infusion of dopamine (DA) into the nucleus accumbens (ACB) were investigated. Dopamine (25 μg/24 hr), infused into the nucleus accumbens for 13 days, caused hyperactivity, with two peaks occurring on days 3–4 and 9–11. Glycine (12.5 or 25 μg/24 hr) infused into the nucleus accumbens on its own did not alter the locomotor activity, yet when infused at the same time as DA (25 μg/24 hr), glycine (12.5 or 25 μg/24 hr) inhibited the development of the first peak of hyperactivity induced by DA, with no effect on the second peak. A larger dose of glycine (50 μg/24 hr), infused alone, significantly increased locomotor activity, and a combination of this dose with DA (25 μg/24 hr), led to a temporal shift in the response to DA such that the first peak of hyperactivity was delayed to “fuse” with the second peak. The locomotor response to a threshold dose of DA (6.25 μg/24 hr) plus glycine (50 μg/24 hr) was no greater than could be accounted for by the hyperactivity response to glycine alone (50 μg/24 hr). Strychnine (10 μg/24 hr), infused into the nucleus accumbens, produced no alteration in locomotor activity. Similarly, when infused together with DA (25 μg/24 hr), strychnine (10 μg/24 hr) caused no significant alteration in the phasic hyperactivity induced by DA. However, strychnine (10 μg/24 hr), infused together with DA and glycine (25 and 12.5 μg/24 hr respectively), prevented the inhibition by glycine of the first peak of hyperactivity induced by DA. The results indicate that while glycine may not normally exert a tonic modulatory influence on those mechanisms in the nucleus accumbens which regulate locomotor activity, when applied exogenously glycine can partially moderate the locomotor response to DA, through an action on strychnine-sensitive receptors.