蓝斑核内注入乙酰胆碱、新斯的明及胆碱能受体阻断剂对迷走—加压反应的影响

采用微量注射药物的方法，研究了４７只大鼠蓝斑核内注入新斯的明、乙酰胆碱及受体阻断剂对迷走—加压反应的影响．结果表明，蓝斑（ＬＣ）内注入新斯的明及乙酰胆碱，迷走—加压反应加强；注入阿托品加压反应减弱；注入六甲双胺加压反应与注药前无明显改变．结果提示，ＬＣ参与迷走—加压反应，并且是该反应产生通路中一个重要组成部分．ＬＣ内的乙酰胆碱经Ｍ受体加强迷走—加压反应．     

Acetylcholine induced endothelial-dependent vasodilation increases as artery diameter decreases in the rabbit ear

Summary Isolated resistance vessels in the rabbit ear preconstricted with histamine were relaxed by acetylcholine by a proportionately greater amount than the central ear artery. The relaxation was antagonized by atropine and also by endothelium removal. Our studies represent the first direct evidence that endothelium-dependent dilation can occur in resistance vessels.Acknowledgments. We thank Christine Quinn for her careful technical assistance in the use of the myographs and Daniel Netto for construction of the small vessel myographs. The tungsten wire used for mounting the vessels was given by Westinghouse Corporation Lamp Division. This work was supported by American Heart Association Fellowship 608 and National Heart, Lung, and Blood Institute Grant HL-32985.     

Genetic and pharmacological models of cholinergic supersensitivity and affective disorders

Summary Increased muscarinic sensitivity has been associated with altered hormonal states (hypothyroidism and hyperadrenocorticism), chronic administration of muscarinic antagonists or antidepressants with muscarinic actions, selective breeding for anticholinesterase sensitivity, and certain inbred strains of rats and mice. Thus, both genetic and environmental factors may influence muscarinic receptor sensitivity. The reasonably detailed studies on the selectively-bred rats have revealed that the Flinders Sensitive Line (FSL) rats weigh less, are less active, are more sensitive to muscarinic agonists and to stressors, and have higher concentrations of hippocampal and striatal muscarinic receptors than normal, or the selectively-bred, Flinders Resistant Line (FRL) rats. Thus, there are a number of parallels between FSL rats and depressed humans. The FSL rats may be the first animal model of depression to mimic the actual trait of depression, and not just the state.     

翠云草平喘作用的实验研究

目的:观察翠云草水提物和醇提物的平喘作用。方法:以组胺和乙酰胆碱引起正常豚鼠支气管收缩和以卵白蛋白诱发的致敏豚鼠支气管收缩。结果:翠云草水提物可显著延长药物引喘和卵白蛋白气雾吸入引喘所致豚鼠抽搐的潜伏期(P<0.01)。结论:翠云草水提物具有平喘作用。     

大鼠在空间辨别性学习记忆时海马CA1,CA3区和DG的ACh能纤维和星形胶质细胞的变化

目的通过建立大鼠空间辨别性学习记忆的动物模型,观察大鼠海马CA1,CA3区和齿状回(DG)的乙酰胆碱(ACh)能纤维密度和含量的变化以及星形胶质细胞的数量及其胶质原纤维酸性蛋白(GFAP)表达的变化,从形态学上探讨中枢ACh和星形胶质细胞与空间辨别性学习记忆的关系.方法建立空间辨别性学习记忆的动物模型,采用乙酰胆碱酯酶(AChE)的组织化学染色及GFAP标记星形胶质细胞.并用显微镜方格目测系统和图像分析仪对大鼠海马CA1,CA3区及DG的GFAP免疫阳性星形胶质细胞的数量及其GFAP表达进行检测.结果模型组与对照组相比大鼠各观察部位的AChE阳性纤维的密度和含量均增高,有显著性差异(P<0.05).而空白组和游水组相比大鼠各观察部位的AChE阳性纤维的密度和含量均无显著性差异(P>0.05),模型组内各组间两两比较大鼠各观察部位的AChE阳性纤维的密度和含量均无显著性差异(P>0.05);模型组与对照组相比大鼠各观察部位的星形胶质细胞的数量及其GFAP的表达均增加,有显著性差异(P<0.05).而空白组和游水组相比大鼠各观察部位的星形胶质细胞的数量及其GFAP的表达均无显著性差异(P>0.05),模型组内各组间两两比较大鼠各观察部位的星形胶质细胞的数量及其GFAP的表达均无显著性差异(P>0.05).结论在空间辨别性学习记忆过程中,大鼠各观察部位的AChE阳性纤维的密度和含量增高,说明中枢ACh参与空间辨别性学习记忆过程;在空间辨别性学习记忆过程中,大鼠各观察部位的星形胶质细胞的数量及其GFAP表达的增加,说明星形胶质细胞参与空间辨别性学习记忆过程.     

Neuronal nicotinic receptors: insights gained from gene knockout an knocking mutant mice

Neuronal nicotinic acetylcholine receptors are ligand-gated ion channels that subserve a range of functions in the brain and peripheral nervous system. They are pentamers variously composed of (₂– ₁₀) and subunits ( ₂– ₄). Pharmacological and ligand-binding studies have shown that the different subunits vary in their distribution and channel properties, but precise delineation of the in vivo function of individual subunits has been hampered by lack of subunit-specific antagonists. The development of transgenic mice with targeted deletions of specific subunits (knockout mice) or mutations in critical receptor domains (knockin mice) has extended understanding of nicotinic receptors, revealing that some subunits are necessary for viability, whereas others mediate modulatory effects on learning and memory, locomotion, anxiety, nociception, dopaminergic neurotransmission, seizure threshold, development of the visual system and autonomic function. In some cases, studies of transgenic mice have confirmed expectations derived from pharmacological and expression studies, but in other cases, compensation by related subunits has revealed a degree of functional redundancy not predicted by previous approaches.Received 19 September 2002; received after revision 12 November 2002; accepted 11 December 2002