乙酰胆碱、阿托品、毛果芸香碱在痛觉调制中对大鼠蓝斑核神经元形态的影响

目的 研究乙酰胆碱(ACh)、阿托品、毛果芸香碱与正常大鼠蓝斑核(LC)在痛觉调制中的作用及其相互关系.方法 采用电生理学与侧脑室给药的方法,以电脉冲刺激坐骨神经作为伤害性刺激,用玻璃微电极引导LC中痛反应神经元的电变化.观察ACh、阿托品、毛果芸香碱对LC中神经元形态学改变的影响.结果 ACh可使LC内神经元形态发生改变,即神经元体积变大、外形不规则,细胞核轻度水肿等.M受体拮抗剂阿托品能阻断上述作用,使神经元结构基本恢复正常.M受体激动剂毛果芸香碱能产生与ACh相似的效应.结论 外源性ACh不仅能加强大鼠LC中痛反应神经元的电活动,而且使神经元的形态也发生了相应的改变,表现为易化疼痛效应.揭示,ACh的易化疼痛作用主要是通过M受体介导而实现的,LC内神经元形态的改变进一步证实ACh和LC在痛觉调制中起重要作用.     

L-PGDS在匹罗卡品诱导癫(痫)大鼠海马组织中的表达及作用

目的:探讨脂质运载蛋白型前列腺素D合成酶(Lipocalin-type prostaglandin D syn-thase,L-PGDS)在匹罗卡品诱导的癫(痫)大鼠海马脑组织中的表达变化及意义.方法:35只SD雄性大鼠随机分成对照组和模型组,模型组依据观察时间点不同又分成建模后id、3d、7d、14 d、30 d和60d6个亚组,每组各5只大鼠.模型组大鼠用氯化锂-匹罗卡品诱导癫(痫)持续状态后,用蛋白免疫印迹检测大鼠海马组织内L-PGDS蛋白表达水平,并用免疫荧光双标技术对L-PGDS进行海马区细胞定位.结果:大鼠癫(痫)持续状态后第1天,海马组织内L-PGDS蛋白表达水平较对照组有所升高,随着时间的延长,L-PGDS蛋白表达水平逐渐升高,与对照组比较差异有统计学意义(P＜0.05).免疫荧光双标检测发现L-PGDS主要表达于神经元的树突和星型胶质细胞的胞质胞浆中.结论:L-PGDS在癫(痫)模型中表达异常升高,可能参与了癫(痫)的发生发展过程,有望成为临床癫(痫)诊断的一个分子标志物和新的抗癫(痫)药物治疗的靶点.     

比较国产与进口复方噻吗洛尔滴眼液对家兔瞳孔和眼压的影响

目的 :比较复方噻吗洛尔国产滴眼液 (含0 .5 %噻吗洛尔和 2 %硝酸毛果芸香碱 )和进口滴眼液 (含 0 .5 %噻吗洛尔和 2 %盐酸毛果芸香碱 )对家兔瞳孔和眼压的影响。方法 :测量正常家兔瞳孔直径变化 ,制备水负荷高眼压兔模型并用压陷式眼压计测量家兔眼压。结果 :国产和进口滴眼液在给药后 15～ 12 0min ,家兔瞳孔明显缩小 ,较对照组眼压明显下降 ,2组间无显著统计差异。结论 :含不同毛果芸香碱盐基的复方噻吗洛尔国产滴眼液与进口滴眼液均具有明显缩瞳和降眼压作用 ,其药理作用强度和作用持续时间无明显差异。     

Dissociation of the immunoreactivity of synaptophysin and GAP-43 during the acute and latent phases of the lithium-pilocarpine model in the immature and adult rat

RATIONALE: Lithium-pilocarpine-induced status epilepticus (SE) generates neuronal lesions in the limbic forebrain, cerebral cortex and thalamus that lead to circuit reorganization and spontaneous recurrent seizures. The process of reorganization in regions with neuronal damage is not fully clarified. METHODS: In the present study, we evaluated by immunohistochemistry the early reorganization during the latent period with two neuronal markers, synaptophysin and growth-associated protein 43 (GAP-43) in rats subjected to SE at PN21 and as adults. RESULTS: Synaptophysin immunoreactivity increased between 24 h and 3 weeks post-SE in regions with severe and rapidly occurring neuronal loss, namely thalamus, amygdala, piriform and entorhinal cortices. GAP-43 expression decreased at 1 and 3 weeks in the same regions. The immunoreactivity of synaptophysin and GAP-43 increased in the inner molecular layer of dentate gyrus from 24 h after SE, and decreased in the outer molecular layer from 72 h after SE. These changes likely result from the death of hilar neurons and the reduction of the input from the entorhinal cortex. In 21-day-old rats that experience less SE-induced neuronal loss, increased immunoreactivity of synaptophysin was only found in piriform and entorhinal cortex while no changes occurred in GAP-43 expression. CONCLUSION: These findings suggest that there is an age-related relation between the extent and rapidity of the process of neuronal death and the expression of these markers. Synaptophysin appears to be a more sensitive marker of plasticity induced by SE than GAP-43.     

匹罗卡品诱导颞叶癫大鼠海马CA1区代谢型谷氨酸受体1、4、7的表达变化

目的 观察匹罗卡品诱导的颞叶癫(癎)大鼠海马CA1区代谢型谷氨酸受体(mGluR)1、4、7的表达变化.方法 56只SD大鼠随机分为对照组、癫(癎)状态(SE)2 h组、SE 12 h组、SE 24 h组、SE 72 h组、SE 7 d组和SE 14 d组,每组8只.SE各组腹腔注射325 mg/kg匹罗卡品建立癫(癎)模型,对照组注射等量生理盐水.采用RT-PCR和免疫组织化学方法检测各组大鼠海马CA1 区mGluR1、4、7 mRNA和mGluR1蛋白的表达.结果 RT-PCR检测显示,SE 24 h组mGluR1 mRNA表达较对照组显著降低,而SE 7 d组则显著增加(P<0.05);SE各组mGluR4 mRNA表达与对照组差异无统计学意义(P>0.05);SE 12 h组、SE 24 h组、SE 72 h组和sE 14 d组mGluR7 mRNA表达较对照组显著降低(P<0.05).免疫组织化学检测显示,mGluRl蛋白主要存在于细胞膜上,其表达变化规律与mGluR1 mRNA一致.结论 mGluR1、4、7可能参与难治性癫(癎)的发病过程.     

二阶导数光谱法测定硝酸毛果芸香碱滴眼液的含量

本文采用二阶导数光谱法测定硝酸毛果芸香碱滴眼液的含量,以230nm 为测定波长,可排除附加剂的干扰,快速简便。平均回收率99.99%,变异系数0.16%。     

Effect of pilocarpine on substance P and calcitonin gene‐related peptide releases correlate with salivary secretion in human saliva and plasma

What is known and Objective:  Pilocarpine, a muscarinic receptor agonist, has been used for the treatment of dry mouth. Salivary glands are supplied with nerve fibres that contain neuropeptides, such as substance P, calcitonin gene‐related peptide (CGRP) and vasoactive intestinal polypeptide (VIP), which are important modulators of salivation. It is known that measurement of salivary and plasma levels of neuropeptides is useful for assessing the dose–pharmacological effect relationship of drugs. The relationship between the action of pilocarpine and neuropeptides in humans has not been studied. Moreover, studies evaluate the usefulness of drug salivary levels in the pharmacological evaluation of drugs are scarce. The aim of this study was to examine the effects of pilocarpine on the levels of substance P‐, CGRP‐ and VIP‐like immunoreactive substances (IS) in saliva and plasma taken in healthy humans. Methods:  Five healthy male subjects participated in this study. Pilocarpine tablet (10 mg) or placebo tablet was orally administered with 100 mL of water. Each subject was administered placebo and drug with an interval of 4 weeks in between. Saliva was sampled before and at 20, 40, 60, 90, 120, 180 and 240 min after administration of the test substances. Venous blood samples (10 mL) were also taken from a forearm vein at each time interval. The samples were then enzyme immunoassayed using a highly sensitive system for substance P‐, CGRP‐ and VIP‐IS. The amount of saliva was measured by the Saxon test. Results:  A single oral administration of pilocarpine increased the release of salivary substance P‐IS (the area under the concentration‐time curve: AUC_{0→240 min}) compared with the placebo. Pilocarpine also significantly increased the release of salivary CGRP‐IS (AUC_{0→240 min}). Pilocarpine significantly increased the release of plasma CGRP‐IS. The salivary volume correlated with the salivary level of substance P and CGRP‐IS (r = 0·84, P < 0·05 and r = 0·59, P < 0·05, respectively). AUC_{0→240 min} for substance P‐IS in saliva correlated with that for plasma (r = 0·78, P < 0·05). What is new and Conclusion:  Pilocarpine increases the release of salivary substance P and CGRP‐IS. This suggests that one mechanism by which pilocarpine improves dry mouth is by local stimulation of neuropeptidergic nerves. Moreover, saliva levels of substance P showed good correlation with the plasma levels. The substance P levels in saliva and plasma may be good indicators of the effects of drugs used in dry mouth/xerostomic patients.