消融右肺动脉神经节丛对肾上腺素能刺激和胆碱能刺激诱发房颤的影响

目的：探讨右肺动脉神经节丛（RPVGP）消融对胆碱能及儿茶酚胺诱发房颤的影响。方法：20只犬麻醉开胸后,暴露RPVGP,分别在消融RPVGP前后,经股静脉静滴乙酰胆碱（ACh）及儿茶酚胺。测量房颤诱发率及两类递质诱发房颤的阈浓度。结果：RPVGP消融前,静滴Ach和异丙基肾上腺素（IPA）及肾上腺素（EPI）（1～100μmol/l）均可诱发AF,诱发率100%。Ach、IPA和EPI的诱发阈浓度分别为2.6±0.3μmol/l,3.3±0.2μmol/l,5.6±0.2μmol/l。RPVGP消融后,Ach及儿茶酚胺的AF诱发率分别降至10%及35%,且三种递质的诱发阈浓度分别提高至2.6±0.3μmol/l、22.5±2.4μmol/l和26.±2.6μmol/（lP〈0.05）。结论：消融RPVGP使乙酰胆碱和儿茶酚胺诱发房颤的阈浓度增高,并降低此二类介质的房颤诱发率。     

急性重度敌敌畏中毒患者血清儿茶酚胺水平与其心脏损伤的关系

目的:探讨急性重度敌敌畏中毒患者血清儿茶酚胺水平与其心脏损伤的关系。方法:选取我院2009年12月至2011年12月收治的急性重度敌敌畏中毒患者40例,接受阿托品和氯解磷定等常规治疗,检测患者入院第1、3、5天血清肌酸激酶(CK-MB)、心肌肌钙蛋(CTNI)、胆碱酯酶(AchE)、乙酰胆碱(Ach)、肾上腺素(EPI)和去甲肾上腺素(NorP)等指标,分析患者血清儿茶酚胺水平与其心脏损伤的关系。结果:40例患者中,34例存活,6例死亡;窦性心动过速35例,心电图(ECG)ST-T改变36例;血清CK-MB、CTNI入院第1、3、5天相比,先升高后降低,出院时降至正常,变化差异有统计学意义(CK-MB:H=8.782,P=0.002;CTNI:H=5.017,P=0.024)。Ach入院第1天时最高,逐渐降低,出院时恢复到正常水平,变化差异有统计学意义(H=9.235,P=0.002;AchE入院第1天时最低,逐渐升高至正常,变化差异有统计学意义(H=46.891,P=0.001)。肾上腺素(EPI)和去甲肾上腺素(NorP)代表儿茶酚胺的变化,入院当天为峰值,其后均逐渐下降,出院恢复正常,变化差异有统计学意义(EPI:H=16.031,P=0.021;NorP:H=57.913,P=0.025)。进一步分析显示EPI和与NorP水平分别与CK-MB和CTNII呈显著正相关,差异均具有统计学意义(P0.05)。结论:敌敌畏中毒时,儿茶酚胺与乙酰胆碱的释放增多,可能引起心肌损害或加重心肌缺血的严重程度。     

花椒挥发油对离体豚鼠气管平滑肌作用的实验研究

目的研究花椒挥发油对组胺(Histamine,His)、乙酰胆碱(Acetylcholine,Ach)诱发的豚鼠离体气管条收缩作用的影响,以及作用的量效关系,为研发平喘类中药奠定基础。方法采用Medlab生物信号采集处理系统利用定量药理分析方法分别测定:(1)His的量效曲线;(2)Ach的量效曲线;(3)不同浓度的花椒挥发油对His诱发的豚鼠离体气管条收缩的影响;(4)不同浓度花椒挥发油对Ach诱发的豚鼠离体气管条收缩的影响。结果His、Ach在体外引起了豚鼠离体气管条的浓度依赖性的收缩,其中His与Ach在10-2mol/L时均可以使气管条收缩达到最大值,花椒挥发油对His、Ach诱发的支气管收缩均有抑制作用,在花椒挥发油浓度达0.48 g/L时抑制率为49%;但对Ach诱发的支气管收缩在剂量为0.48 g/L时抑制率仅达到26%,抑制作用明显弱于His;结论花椒挥发油在体外浓度为0.08~0.48 g/L时均能有效地抑制His、Ach诱发的支气管收缩,对His诱导的豚鼠气管平滑肌收缩的抑制作用强于Ach,提示花椒挥发油对过敏性刺激诱发的哮喘有较好的抑制作用,将为开发抗过敏性哮喘疾病的中药研发奠定基础。     

家兔隔核中去甲肾上腺素对皮肤与内脏痛阈的影响

本工作以电刺激内脏大神经或耳尖部皮肤测定清醒家兔内脏痛阈或皮肤痛阈,以探讨隔核去甲肾上腺素在内脏镇痛和皮肤镇痛中的作用以及与中脑导水管周围灰质(PAG)中内阿片肽系统的关系。实验观察到,双侧隔核内微量注射α受体激动剂可乐宁(10μg/2μl)或α受体阻断剂酚妥拉明(10μg/2μl)对内脏痛阈无明显影响。注入β受体激动剂异丙肾上腺素(1μg/2μl)使内脏痛阐明显升高;而注入β受体阻断剂心得安(1Cμg/2μl)则内脏痛阈明显降低。隔核内注入酚妥拉明(10μg/2μl)或心得安(10μg/2μl)均可使皮肤痛阈明显提高。提示,隔核内NA通过β受体调制内脏痛;通过α受体和β受体调制皮肤痛。隔核内注入异丙肾上腺素(1μg/2μl)明显地镇内脏痛,此作用可被PAG内注射纳洛酮(1μg/2μl)或注射抗亮啡肽抗血清(1:20,000)所减弱;但可使PAG内亮啡肽样物质释放量增加。这提示,隔核内NA的镇内脏痛作用与PAG的内阿片肽系统有关;其中亮非肽在这一过程中具有重要作用。     

麻黄碱抑制小鼠输精管电场刺激致收缩的机制

麻黄碱(10 nmol/L~(-0.1) mmol/L)对电场刺激所致输精管收缩的浓度依赖性抑制作用可被育亨宾(0.1 μmol/L)减弱。去甲肾上腺素(0.1 nmol/L~(-10)μmol/L )和酪胺(0.1 μmol/L~(-0.1) mmol/L)也有类似麻黄碱的作用,去氧肾上腺素则缺乏此种作用。利血平处理和可卡因(10 μmol/L)可减弱麻黄碱和酪胺的抑制效应,但能增敏去甲肾上腺素的作用。高 Ca~( )和4-氨基吡啶(50 μmol/L)明显减弱甚至取消麻黄碱对电场刺激的抑制效应。以上结果提示麻黄碱抑制电场刺激所引起的输精管收缩。至少部分通过促进神经末梢释放去甲肾上腺素间接作用,后者激动突触前α_2-肾上腺素受体,从而抑制去甲肾上腺素的进一步释放。麻黄碱和其释放的去甲肾上腺素的作用,又可能与阻遏 Ca~( )内流有关。     

家兔蓝斑复合核区微量注入去甲肾上腺素能激动剂和拮抗剂对呼吸和血压的效应

于麻醉家兔脑桥蓝斑复合核(LC)区微量注入去甲肾上腺素溶液(0.1mol,1或2μl),引起肺通气量增加和动脉血压升高。上、下丘间全离断脑干或横断中脑被盖及其背侧结构,不能消除此效应。LC 区同一点施加电刺激引起相同效应。LC 区注入α-受体阻断剂酚妥拉明(0.1mol,2μl)、妥拉苏林(0.1mol,2μl)或 α-受体激动剂氯压啶(0.02mol或0.1mol,2μl),使肺通气量明显减少,而对血压影响不大。本结果提示LC及附近被盖区的去甲肾上腺素能传人纤维可通过 α-受体调制该区的植物性机能。     

丹参酮Ⅱ-A磺酸钠对分离的豚鼠心室肌单细胞慢反应动作电位的作用

分离的成年豚鼠心室肌单细胞在高钾(25mmol/L)溶液中部分除极化使钠通道失活,用细胞内刺激诱发慢反应动作电位。20μmol/L 的丹参酮Ⅱ-A 磺酸钠对这种慢反应动作电位有明显的抑制作用。在1—20μmol/L 浓度范围内,丹参酮Ⅱ-A 磺酸钠对0.28μmol/L 的异丙肾上腺素强化的慢反应动作电位有浓度依赖性抑制作用。而且,随异丙肾上腺素浓度的增加(69 nmol/L—0.55μmol/L)抑制作用更加明显。以上结果提示丹参酮 Ⅱ-A 磺酸钠可能是一种钙拮抗剂。50—100μmol/L 的丹参酮 Ⅱ-A 磺酸钠使分离的成年豚鼠心室肌单细胞快反应动作电位的幅度降低,达峰值的时间延长。提示高浓度的丹参酮 Ⅱ-A 磺酸钠对钠通道也有一定的阻断作用。     

白桦树羽扇豆烷型三萜类化合物与抑制PTP1B活性研究

蛋白酪氨酸磷酸酯酶1B(Protein tyrosine phosphatase1B;PTP1B)在胰岛素信号传递过程中起负调控作用,亦是研究治疗2型糖尿病的重要靶点。利用PTP1B生物活性导向分离方法,从白桦树皮的正己烷提取物中分离得到7个羽扇豆烷型三萜类化合物。经过光谱分析和文献比较,确定分离得到的7个化合物为:羽扇烯酮(1),羽扇豆醇(2),桦木酸(3),白桦脂醛(4),白桦脂酸(5),算盘子酮醇(6)和白桦脂醇(7)。其有效抑制PTP1B活性值(IC50)分别为:5.6±0.3μmol/L,4.1±0.2μmol/L,7.2±0.3μmol/L,12.6±0.4μmol/L,11.6±0.3μmol/L,9.6±0.4μmol/L和13.6±0.5μmol/L。     

去甲肾上腺素、乙酰胆碱对绵羊心肌浦肯野纤维瞬时性内向离子流的影响

用电压箝制术观察了去甲肾上腺素、乙酰胆碱对绵羊浦肯野纤维由乙酰毒毛旋花子甙元诱发的瞬时性内向离子流(I_Ti)的效应。当乙酰毒毛旋花子甙元浓度为4.5×10~(-8)mol/L 时,诱发出的I_(T1)稳定并能维持约1.5h。去甲肾上腺素1.5×10~(-6)mol/L,可使I_(Ti)的峰值由11.4±2.5nA 增加到14.5±4.1nA(n=11,P相似文献   

重组BHMT对高同型半胱氨酸血症大鼠的影响

目的探讨重组BHMT对大鼠HHcy血症的防治作用。方法用含2%蛋氨酸(methionine,Met)饲料诱发HHcy的大鼠,经尾静脉注射BHMT后,观察模型大鼠血浆中同型半胱氨酸(homocysteine,Hcy)浓度、LDH酶活性及HDL/LDL的影响。结果重组BHMT能将HHcy组大鼠血浆中Hcy浓度(23.70±6.75)μmol/L显著降低为(14.61±2.80)μmol/L(P<0.05),LDH酶活性由(209.57±10.22)U/L降低为(225.04±30.47)U/L(P<0.05),对脂蛋白HDL/LDL基本没有影响。结论重组BHMT对高同型半胱氨酸血症有一定的治疗作用。     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

The early development of the tail and the transformation of the shape of the nucleus of the spermatid of the domestic fowl,Gallus gallus

Summary The differentiation of the spermatid, especially in reference to the formation of the flagellum, and transformation of the shape of the nucleus was investigated in the domestic fowl.In the early stage of the spermatid, a prominent Golgi apparatus appears around the centrioles. The Golgi vesicles then surround the axial-filament complex which develops from the distal centriole. These vesicles fuse to form continuous membrane at the earliest stage of flagellar formation, and in the succeeding stage Golgi lamellae are attached to the plasma membrane of the developing flagellum. From these observations, it is assumed that Golgi apparatus may be a source of the membrane system of the flagellum.The microtubules distributed around the nucleus form the circular manchette. The anterior region of the nucleus with the manchette is cylindrical in shape and the posterior region without it remains irregular in shape. When the circular manchette has been completed, the whole nucleus acquires a slender cylindrical shape. The circular manchette then changes into the longitudinal manchette. The nuclei of spermatids without a longitudinal manchette are abnormal in shape. In view of these observations it is assumed that the nuclear shaping of the spermatid may be accomplished by circular manchette and the maintenance of shape of the elongated nucleus by longitudinal manchette.The authors wish to thank Mr. Takayuki Mori for his helpful suggestions and technical advices     

Characterization of the composition of the aqueous humor and the vitreous body of the eye of the frog Rana temporaria L

This study aimed to analyze the aqueous humor (AH) and the vitreous body (VB) of the eye of the adult frog Rana temporaria L. as a representative species of amphibians, which lead a semi-terrestrial life. The presence of collagen, albumin, uric acid and electron donors was shown in both media; however, there are slight differences in their concentrations. To determine collagen, a spectral-fluorescent probe, cyanine dye, was used. The presence of collagen in AH of the frog was found at the first time. The total content of electron donors (ascorbic and uric acids, tryptophan, and tyrosine) in VB and HA was roughly estimated at ~ 1.5 × 10^− 4 mol/L. Both VB and AH absorb light in similar UV regions. The total protein and albumin contents in AH were found to be somewhat higher than those in VB. The uric acid content was at an equally low level in both intraocular media. It is supposed that the similarity of VB and AH compositions shown in this work is due to some exchange between VB and AH contents in the course of accommodation. The role of intraocular fluids in physiological functions of the eye and in protecting the retina against UV light is discussed.