催产素对蟾蜍离体心脏活动影响的研究

为了探讨不同浓度催产素(oxytocin,OT)对蟾蜍离体心脏心肌收缩力和心率的影响,试验采用斯氏离体蛙心灌流的方法,灌流液总量为1.0~1.5 m L,依次滴加浓度为0.001,0.002,0.003,0.004,0.005,0.008,0.010 mg/m L的催产素,并应用BL-420F生物机能实验系统进行记录和观察对蟾蜍离体心脏收缩活动的影响。结果表明:不同浓度催产素可以有效抑制蟾蜍离体心脏的活动。在低浓度时,即0.001,0.002,0.003 mg/m L催产素对离体心脏心肌收缩力与心率的影响不显著(P0.05);而在高浓度时,即0.008,0.010 mg/m L催产素对蟾蜍离体心脏心肌收缩力与心率的影响显著(P0.05)。说明催产素可以有效抑制蟾蜍离体心脏的活动。     

龙胆水煮液对蟾蜍离体心脏活动的影响

为了观察不同浓度龙胆水煮液对蟾蜍离体心脏功能的影响,试验采用斯氏离体蛙心灌流法,在保持液面为1.0 cm的情况下,分别以0.03,0.05,0.07,0.10 g/m L四种浓度的龙胆水煮液分别对蟾蜍离体心脏进行灌流,记录与观察蟾蜍离体心脏的收缩活动。结果表明:对蟾蜍离体心脏灌流不同浓度的龙胆水煮液时,均可使其心脏收缩振幅明显降低;同时随着龙胆水煮液浓度的增加对蟾蜍离体心脏的心率也具有明显的抑制作用。说明龙胆水煮液可明显抑制蟾蜍离体心脏的心肌收缩力,对心率有减慢作用,且阿托品和心得安不能阻断这种作用。     

梅花鹿和驯鹿外周血和茸血对牛蛙离体心脏心肌收缩力和心率的影响

为探讨鹿血对牛蛙离体心脏收缩力和心率的影响,采用斯氏法离体蛙心,分别用不同的鹿血对离体心脏进行灌流,用BL 420E生物技能试验系统记录离体心脏给药前、后心肌收缩力和心率的变化。试验结果表明:梅花鹿外周血、梅花鹿茸血、驯鹿外周血和驯鹿茸血与任氏液对照组相比心肌收缩力增加42.27%¹26.62%,差异极显著(P<0.01),其中梅花鹿外周血和驯鹿外周血较比梅花鹿茸血和驯鹿茸血对增强离体蛙心心肌收缩力更为明显,但对各组间的心率没有影响(P>0.05)。     

铜缺乏对奶牛红细胞及组织细胞膜ATP酶活性的影响

为探讨铜缺乏对奶牛红细胞及组织细胞膜ATP活性的影响，在调查铜缺乏奶牛水土食物链微量元素状态的基础上，首次测度了病区6头发病犊奶牛（Ⅱ组）及该地区20头同年生临床健康奶牛（IH组，血清铜低于0.56mg/kg）红细胞膜Na^ -K^ -ATP酶、Ca^2 -ATP酶及Mg^2 -ATP酶的活性，对20头IH组奶牛进行为期80d的补铜试验（含铜40mg/kg干饲料），以20头健区同年生健康奶犊牛作为对照（HH组，全血铜大于０.85mg/L）。同时测试了剖杀后６头病牛及健康牛组织细胞膜ＡＴＰ酶的活性。结果表明：Ⅱ组奶牛红细胞膜ＡＴＰ酶活性显著低于ＨＨ组及ＩＨ组。补铜后４０d，ＩＨ组奶牛红细胞膜Na^ -K^ -ATP酶均显著升高，病牛肝、脾、肾、大脑、小脑、淋巴结等组织细胞膜Na^ -K^ -ATP酶、Ca^2 -ATP酶活性显著低于对照组。结论：铜缺乏较为严重地影响了奶牛红细胞及组织膜ＡＴＰ酶的活性，抑制了这些组织的正常生理功能。     

几种化学离子与药物对蟾蜍心肌细胞的作用分析

用斯氏离体蟾蜍心脏灌流法研究两栖动物心脏活动规律及其特点 ,并探讨几种离子与药物对心肌细胞的作用机制。利用中华大蟾蜍制备离体心脏标本 ,分别灌流 Na Cl、Ca Cl2 、KCl、肾上腺素及乙酰胆碱 ,用张力换能器与电脑记录仪描记心搏曲线予以记录和分析。结果表明 :心肌细胞外高 Na ,动作电位 0期除极速度和幅度都减小 ,传导性降低。Ca2 直接参与心肌兴奋 -收缩耦联作用 ,高 Ca2 时 ,Ca2 内流增多 ,心肌收缩性增强。 K 和 Ca2 存在竞争性抑制关系 ,可使 Ca2 内流减小 ,心肌收缩性减弱。肾上腺素与 β肾上腺素能受体结合 ,产生正性变时和变力作用 ,使心输出量增加 ,心肌收缩性增强。乙酰胆碱可提高膜上 K 通道的通透性 ,K 外流增加 ,Ca2 内流减少 ,心肌收缩性降低     

高海拔地区牦牛心肌骨骼肌ATP酶活性的测定

为了探讨高原动物对高原低氧的适应机制,采用标准ATP酶测试盒对青海省(平均海拔4 000 m)16头成年牦牛心肌、骨骼肌ATP酶活性进行了测定和分析.结果:Na+ -K+ -ATP,Mg2+ -ATP,Ca2+ ATP和Ca2+-Mg2+-ATP 4种酶活性在骨骼肌线粒体中分别为3.65±1.31(μmolP/mg蛋白·h,下同),2.70士1.36,2.87±1.23和4.08士1.30;在心肌线粒体中分别为4.44±1.19,2.42士0.87,2.29±0.57和3.62±0.92;在骨骼肌组织中分别为2.02±0.80,1.54士0.36,1.69士0.91和2.02±0.96;在心肌组织中分别为1.41士0.67,1.04士0.51,1.24±0.54和1.42±0.60;骨骼肌、心肌线粒体中4种ATP酶活性均显著高于骨骼肌、心肌组织(P＜0.05).     

细胞钙超载与鸡柔嫩艾美耳球虫病损伤关系

为探讨鸡柔嫩艾美耳球虫（E．tenella）宿主细胞损伤与钙超载的关系，采用组织定量检测、Von Kossa钙染色、焦锑酸钾电镜细胞化学技术对使用和未使用钙离子阻断剂的E．tenella感染鸡盲肠组织的细胞沉积钙、ATP酶、磷脂酶A2（PLA2）、游离脂肪酸和盲肠上皮细胞游离Ca^2＋的含量与分布进行了动态测定和分析。结果表明：（1）鸡患柔嫩艾美耳球虫病过程中，宿主细胞内钙和游离Ca^2＋明显增多（P〈0．01），并随盲肠损伤加重而增加；（2）在发病过程中盲肠组织Na^＋-K^＋-ATP酶、Ca^2＋-Mg^2＋-ATP酶、总ATP酶活性均有不同程度的下降，在感染严重期显著低于不感染对照组（P〈0．01）；（3）钙超载盲肠组织的PLA2活性和游离脂肪酸含量明显升高（P〈0．01），表明钙超载是鸡柔嫩艾美耳球虫病的一个重要损伤机制；（4）硝苯地平可以阻止Ca^2＋内流，减少宿主细胞内游离Ca^2＋，减轻宿主细胞的损伤，在本病发生的早期盲肠损伤较轻时，对鸡有一定的保护力，但随着疾病的发展，其作用下降。     

不同发育期大通牦牛心肌、骨骼肌线粒体ATP酶活性的测定

对青海省大通牦牛1、30、180日龄及成年组心肌和骨骼肌线粒体Na+-K+-ATP酶、Mg2+-ATP酶、Ca2+-ATP酶和Ca2+-Mg2+-ATP酶活性进行测定。结果显示,牦牛心肌、骨骼肌线粒体Na+-K+-ATP酶、Mg2+-ATP酶、Ca2+-ATP酶和Ca2+-Mg2+-ATP酶活性在年龄组间差异均不显著(P>0.05)。表明大通牦牛在生长发育阶段心肌、骨骼肌线粒体ATP酶在物质运输、能量转换及信息传递等方面发挥着稳定的作用,且与年龄之间无明显的线性关系。     

内毒素对山羊红细胞膜Ca2+-ATP酶及红细胞内和血清中Ca2+离子浓度的影响

内毒素血症中自由基生成增多。自由基可攻击酶活性部位，使酶蛋白发生结构重构，形成新的聚合物，使原来酶活性丧失或改变。Ca^2＋-ATP酶是红细胞膜上的蛋白之一。Ca^2＋是细胞内第二信使，在细胞外信号传递以及放大过程中起着重要的作用。     

肉鸡腹水综合征患鸡右心组织钙沉积和Ca2+-ATPase活性变化

右心肥大衰竭是腹水综合征患鸡发病的重要环节之一,而心肌细胞内Ca^2＋浓度在调节心脏收缩和舒张功能及其生长方面都起着重要作用。本试验应用右心导管法测定AS患鸡右心压力变化情况,采用焦锑酸钾沉淀法、电镜酶细胞化学法研究AS患鸡右心组织Ca^2＋和钙泵（Ca^2＋-ATPase）活性变化及其精确定位。结果显示AS组肉鸡右心室舒张压极显著高于对照组（P〈0.01）,同时,右心室内压最大变化速率也极显著降低（P〈0.01）;对照组肉鸡右心组织偶见少量散在的Ca^2＋沉淀颗粒,低温诱发AS患鸡右心组织发生了明显的钙沉积;对照组肉鸡的右心组织Ca^2＋-ATPase以高电子密度颗粒分布于肌浆网、线粒体膜等处,AS患鸡心脏组织的Ca^2＋-ATPase的电子密度颗粒显著减少或缺失。本研究揭示,在低温条件下AS患鸡具有明显的右心舒张功能障碍,Ca^2＋浓度增高和Ca^2＋-ATPase功能抑制可能在其中起着重要作用。     

氟对牛脾淋巴细胞膜ATP酶活性的影响

取健康牛脾脏,常规方法分离培养淋巴细胞,用不同浓度氟化钠（NaF）染毒24h。低渗溶胞法提取细胞膜,检测膜上ATP酶活性。结果显示,与对照组相比较,染氟组淋巴细胞膜ATP酶活性降低,组间差异显著或极显著。表明：氟能抑制牛脾淋巴细胞膜ATP酶活性。     

熊胆粉抗乙醇诱导的小鼠肝细胞氧化损伤研究

目的：研究熊胆粉对乙醇诱导的小鼠肝细胞氧化损伤的保护作用。方法：Ⅰ型、Ⅳ型胶原酶和DNA酶联合消化分离、培养小鼠原代肝细胞,乙醇诱导小鼠肝细胞损伤,MTT法检测肝细胞存活率,不同浓度熊胆粉预处理肝细胞,观察培养液中丙二醛（MDA）、还原型谷胱甘肽（GSH）含量和超氧化物歧化酶（SOD）活性。结果：乙醇对肝细胞的损伤呈量效关系,与正常对照组相比,损伤组培养液中MDA含量明显增加,GSH含量显著降低（P〈0.05）。熊胆粉保护各组（125,150,175μg·ml～（-1））与损伤组相比,培养液中MDA含量明显减少（P〈0.05）,GSH含量和SOD活性显著升高（P〈0.05）。结论：熊胆粉对乙醇诱导损伤的肝细胞具有明显的保护作用。     

Altered adenosine triphosphatase activities in pigs with naturally occurring hypertrophic cardiomyopathy

The purpose of this study was to determine whether myocardial adenosine triphosphatase (ATPase) activities were reduced in pigs with naturally occurring hypertrophic cardiomyopathy (HCM). The selection of hearts for the HCM and the normal control groups depended on histological examination. Specific ATPase activity and 5-nucleotidase activity were measured in left ventricular myocardium obtained from HCM (n=7) and normal control (n=7) animals. The histological features of HCM included marked disorientation of muscle cells, thickening of the intramural coronary arterial wall with a narrowed lumen, endocardial fibrosis and myocardial fibrosis. The HCM group showed significant increases in both heart weight (32%) and heart weight to body weight ratio (46%). The total ATPase activity in crude homogenates from the HCM group was significantly decreased by 16%. Azide-sensitive ATPase (mitochondrial ATPase) activity, ouabain-sensitive ATPase (Na⁺,K⁺-ATPase) activity, basal Mg²⁺-ATPase activity and Ca²⁺-ATPase activity were all significantly decreased by 18%, 30%, 20% and 50%, respectively. In contrast, no significant decrease was found in the mean values for 5-nucleotidase activity. These results suggest that myocardial ATPase activities are suppressed in pigs with naturally occurring HCMAbbreviations ATP adenosine triphosphate - gww grams wet weight - HCM hypertrophic cardiomyopathy - Pi inorganic phosphate     

Electrocardiographic surrogates of structural myocardial alterations in the Dorper sheep heart

In this study we evaluated the validity of well-known human electrocardiographic markers of myocardial pathology in Dorper sheep. These markers include: the duration of the QRS complex of premature ventricular complexes (PVCs), the presence of notching of the QRS complex of PVCs and change of the ST-segment of PVCs. It was shown that these three electrocardiographic phenomena correlate with myocardial pathology in the hearts of Dorper sheep. We also describe a new electrocardiographic indicator of myocardial pathology, namely an increase in the frequency of cardiac memory T waves as a new electrocardiographic surrogate for myocardial pathology in the hearts of Dorper sheep.     

Cloning of fox (Vulpes vulpes) Il2, Il6, Il10 and IFNgamma and analysis of their expression by quantitative RT-PCR in fox PBMC after in vitro stimulation by Concanavalin A

The immune response in the fox (Vulpes vulpes), despite the success of the oral rabies vaccine is not well characterised, and specific immunological tools are needed. A quantitative RT-PCR using SyBR Green to investigate fox cytokine expression after antigen PBMC in vitro re-stimulation is presented here. First, we cloned by homology with dog cytokine sequences the fox IL2, IL6, IL10, IFNγ and a partial 18S sequence. Fox specific primers were then defined and used to set up a species-specific quantitative RT-PCR assay using SyBR Green and 18S housekeeping gene as internal standard. The technique was validated using total RNA from fox PBMC stimulated with a polyclonal activator, Concanavaline A.     

Distribution of orally administered aflatoxin B 1 in the tissues and organs of the goat (Capra)]

In the experiment the goat was administered an amount of 450 mg aflatoxin B1. The milk taken during the experiment was lyophilized and aflatoxins B1 and M1 were isolated. After the death of the goat some tissues, blood and bile of the experimental animal were analyzed to find out the aflatoxin content.     

青海地区野生狐狸棘球绦虫感染情况调查研究

野生狐狸是棘球绦虫的主要终末宿主,在棘球蚴病的传播中有重要作用。为了解青海省狐狸中棘球绦虫感染状况,我们用棘球绦虫粪抗原检测试剂盒,对收集于青海省称多县、贵南县、祁连县的野生狐狸粪便进行了检测。结果表明,称多县收集的129份狐狸粪便阳性15份,阳性率11.6%;祁连县收集的84份狐狸粪便阳性3份,阳性率3.6%;贵南县收集的47份狐狸粪便阳性0份。共收集的260份狐狸粪便中阳性18份,平均阳性率7.5%。青海省野生狐狸中有棘球绦虫感染,在棘球蚴防治中应加强野生终末宿主的防治。     

A retrospective report of 90 dogs with suspected cane toad (Bufo marinus) toxicity

OBJECTIVE: To report the clinical characteristics of toad toxicity in domestic dogs in Brisbane. DESIGN: A retrospective analysis of clinical cases. PROCEDURE: All cases of toad poisoning which presented to a northern suburbs emergency clinic in Brisbane over a 30-month period beginning in April 1999 were reviewed. RESULTS: A total of 90 canine cases of suspected toad poisoning were reviewed. Small breed dogs accounted for 76% of cases. Jack Russell, Silky, and Fox Terriers were the most represented breeds. Cases were reported year round, with fewest cases over the winter months. The most common clinical signs were increased salivation (78% of cases), and red oral mucous membranes (63% cases). Seizures occurred in 31% of cases. Generally the outcome was excellent with 96% survival.     

牛乳酪蛋白初级抗菌肽粉乳基料的制备

为制备抗菌活性较好的肽粉乳基料,以新鲜牛乳为原料提取酪蛋白,以酪蛋白酶解物对大肠杆菌、沙门氏菌和金黄色葡萄球菌的抑菌圈直径为指标,从木瓜蛋白酶、碱性蛋白酶、中性蛋白酶和胰蛋白酶中筛选出一种蛋白酶水解牛乳酪蛋白,并通过单因素试验和正交试验确定该酶水解牛乳酪蛋白优化水解条件。结果表明：木瓜蛋白酶水解牛乳酪蛋白,其酶解物对3种菌均有较好的抑制作用;优化水解工艺条件为：酶解温度50℃、酶解时间4.5h、加酶量4500U/g、pH5.5、底物质量浓度6g/100mL;牛乳酪蛋白酶解物及初级肽粉乳基料稳定性均较好。     

Faecal virome of red foxes from peri-urban areas

Red foxes (Vulpes vulpes) are the most abundant carnivore species in the Northern Hemisphere. Since their populations are well established in peri-urban and urban areas, they represent a potential reservoir of viruses that transmit from wildlife to humans or domestic animals. In this study, we evaluated the faecal virome of juvenile and adult foxes from peri-urban areas in central Croatia. The dominating mammalian viruses were fox picobirnavirus and parvovirus. The highest number of viral reads (N = 1412) was attributed to a new fox circovirus and complete viral genome was de novo assembled from the high-throughput sequencing data. Fox circovirus is highly similar to dog circoviruses identified in diseased dogs in USA and Italy, and to a recently discovered circovirus of foxes with neurologic disease from the United Kingdom. Our fox picobirnavirus was more closely related to the porcine and human picobirnaviruses than to known fox picobirnaviruses.