The Effect of Ivermectin on Convulsions in Rats Produced by Lidocaine and Strychnine

Ivermectin is one of the most commonly used drugs in pharmacotherapy of parasitic diseases in domestic and wild animals caused by parasitic nematodes and arthropods. However, ivermectin and other avermectins very often produce side-effects in hosts. The most dominant clinical symptom of ivermectin toxicity in domestic and wild animals is CNS depression. In nematodes, the target site of ivermectin’s action is glutamate-gated chloride-channel receptor and GABA receptor. The depressive effect of ivermectin in mammals might include more than one mechanism; therefore, the anticonvulsive effect of ivermectin against convulsions caused by lidocaine and strychnine was evaluated. Ivermectin antagonized lidocaine- and strychnine-induced convulsions in rats, although these have different mechanisms. In the present study, the anticonvulsive ED₅₀ of ivermectin for lidocaine-induced convulsions was 2.44 mg/kg (95% CL 1.67 to 3.57 mg/kg), whereas for convulsions induced by strychnine it was higher at 4.25 mg/kg (95% CL 2.32 to 3.78 mg/kg). At the same time, both anticonvulsive doses are significantly lower then the observed LD₅₀ of ivermectin (18.20 mg/kg). Furthermore, flumazenil (0.1 and 0.2 mg/kg), an antagonist of benzodiazepine receptors, antagonizes just one part of these anticonvulsive effects of ivermectin. Our results show the significant anticonvulsive properties of ivermectin and support the findings that ivermectin in the CNS of mammals produces multiple inhibitory effects, probably through participation in the function of GABA-sensitive and GABA-insensitive chloride channels.     

复方当归制剂对慢性氟中毒大鼠抗氧化系统的影响

采用Wistar大鼠复制慢性氟中毒模型,口服不同剂量的复方当归制剂,探讨其对慢性氟中毒大鼠的颉颃作用机理。检测各组大鼠血浆超氧化物歧化酶和谷胱甘肽过氧化物酶活性以及丙二醛(MDA)含量。实验结束时,测定血浆和肝、肾组织中的上述各项指标及机体总抗氧化力。结果表明,慢性氟中毒大鼠肾脏的脂质过氧化损伤最为明显,其抗氧化酶活力显著下降,脂质过氧化产物血浆MDA含量明显升高。灌服一定剂量的复方当归制剂能缓解氟中毒大鼠牙齿损伤程度,推迟氟斑牙的发生时间,还能明显增强机体总抗氧化力。     

Magnetic resonance imaging of a brain abscess in a 10-month-old filly

The purpose of this paper was to correlate the magnetic resonance imaging (MRI) characteristics of a mature brain abscess in a horse with histopathologic alterations of brain tissue. Eight months after the onset of clinical signs, MRI of the brain of a 10-month-old filly was performed. A large space-occupying lesion in the right cerebral hemisphere was identified. This space-occupying lesion was delineated by a thick and well-defined capsule that was isointense to brain parenchyma on the T1-weighted images and with a markedly hypointense on the T2-weighted images. The identification of such a capsule is highly diagnostic of a mature brain abscess. The lesion seen on MR images was confirmed at necropsy where a large abscess of the right hemisphere was observed. Streptococcus zooepidemicus and Pseudomonas aeruginosa were isolated from the abscess. Based on histopathologic examination, the signal characteristics of the capsule on T1-weighted and T2-weighted images were found to be due to the presence of numerous hemosiderin-laden macrophages. These results are in agreement with previous studies on human patients. This report confirms the value of MRI in the diagnosis of equine brain diseases.     

纯化的大豆凝集素对大鼠内脏器官发育与免疫功能的影响

试验的目的是研究日粮中不同水平的大豆凝集素(SBA)对大鼠免疫功能的影响。选取30只19日龄断奶的SD雄性大鼠,随机分配到5个日粮处理组中。5个处理组大鼠均采食以玉米淀粉酪蛋白为基础的日粮,每只大鼠均供给7g/d日粮和充足清水,试验进行20d。试验中大鼠的平均初始体重为(77.8±2.6)g,5个处理组的日粮SBA水平分别为0(对照组)、0.5、1.0、1.5mg/g和2.0mg/g。结果表明:日粮中添加SBA,大鼠日增重下降(P<0.01),淋巴细胞刺激指数和细胞因子浓度均下降(P<0.05),另外血浆免疫球蛋白水平也明显下降(P<0.05)。表明日粮添加纯化SBA能够影响大鼠生长性能,并能够影响大鼠的细胞免疫功能和体液免疫功能。     

MCT1抑制剂p-CMB对乙酰胆碱诱导的大鼠胰液分泌的影响

采用在体试验方法研究单羧酸转运蛋白第1亚型（monocarboxylate transporter 1,MCT1）抑制剂（p-chloromercuribenzene sulfonate,p-CMB）对乙酰胆碱（acetylcholine,Ach）诱导的大鼠胰液分泌的影响。Spra-gue-Dwley（SD）雄性大鼠,体重180g-210g,分6组,每组5只,试验前禁食24h,自由饮水。动物麻醉后经外科手术后,每隔10min收集一次胰液,采用Lowry法测定胰液蛋白量,Bernfeld法测定胰酶。结果对照组（-p-CMB）和实验组（＋p-CMB）,在注射1、5、10μg／kg的Ach后对胰液分泌量、胰蛋白分泌量以及胰淀粉酶分泌量都呈现增加作用,注射后1h内达到峰值,之后逐渐降低。然而,试验组的胰液分泌各项指标比对照组的显著减少（P〈0．01）。表明MCT1抑制剂p-CMB减弱了Ach增加大鼠胰液分泌的作用。     

侧脑室注射Leptin对大鼠下丘脑前阿黑皮素mRNA表达的影响

给体重 180～ 2 0 0 g的雌性 SD大鼠侧脑室中注射重组瘦素 (L eptin) 1μg,采用 RT- PCR测定了其下丘脑前阿黑皮素 (POMC) m RNA和 L eptin受体 (OB- R) m RNA的表达水平。结果表明 ,注射重组 L eptin后 ,OB- R基因和 POMC基因表达量均上升 ,与生理盐水注射组、空白对照组相比差异显著 (P<0 .0 5 ,P<0 .0 1)。由此认为 ,L eptin在大鼠下丘脑 POMC的调控功能中起着重要作用     

Imaging suppurative infections of the central nervous system in horses

Suppurative infections are typically caused by pyogenic bacteria, and are characterised by the formation of purulent exudates (pus). These infections may occur anywhere in the body and are particularly life‐threatening when pertaining to the central nervous system (CNS). Suppurative infections of the CNS may be due to trauma, local extension of disease, and haematogenous spread. In horses, suppurative infections are an important cause of morbidity and mortality, but only infrequently involve the CNS. The gross morphology of suppurative inflammation is described as phlegmon, abscess and empyema, with each form having characteristic morphological features that may be identified during advanced imaging of the CNS. In horses with known or suspected suppurative infection of the CNS, imaging may be performed to reduce diagnostic uncertainty, determine prognosis, or to describe the character and extent of the disease to guide case management.     

饲粮添加精氨酸对娩后Wistar大鼠乳腺组织发育及酪蛋白合成的影响

本试验旨在研究饲粮添加精氨酸(Arg)对娩后Wistar大鼠乳腺组织发育及其酪蛋白合成的影响。采用同窝对照的方法,选择同窝12只已受孕的Wistar大鼠,随机平均分为2组。Arg组在基础饲粮中添加与其等量的Arg(饲粮Arg含量1.280%),对照组饲粮用谷氨酸替代Arg组中的Arg以平衡饲粮氮水平。预试期4 d(分娩前4天)和正试期17 d(分娩后17天),结束后采集泌乳大鼠的乳腺组织,制作组织切片并测定其酪蛋白含量。结果表明:Arg能促进乳腺组织的发育,且乳腺腺泡切面面积的极显著增大(P0.01)。另外,Arg对乳腺β-酪蛋白的含量有显著的提高作用(P0.05),同时娩后大鼠体重也有增加的趋势(P0.05)。结果提示,饲粮添加Arg对Wistar大鼠乳腺组织发育及β-酪蛋白的合成有显著的促进作用。     

抗脂肪细胞膜蛋白抗体对试验性肥胖大鼠5种激素水平的影响

为了验证抗脂肪细胞膜蛋白抗体减少动物脂肪沉积的作用效果,并对该抗体用于人类肥胖的治疗提供理论依据和试验资料,本试验分别对4组试验性肥胖大鼠注射0、0.1、0.5、1.0mg/mL剂量的抗脂肪细胞膜蛋白抗体,并检测4周内大鼠血清中5种激素含量及变化。结果显示,试验组血清中胰岛素(INS)含量低于对照组,Ⅰ组与Ⅳ组4周内均差异显著(P0.05);试验组与对照组、胰岛素样生长因子1(IGF-1)含量无显著差异(P0.05);注射抗体后,试验组生长激素(GH)含量显著增高,且Ⅰ、Ⅲ组4周内均差异显著(P0.05);第1周内,试验组三碘甲状腺原氨酸(T3)含量与对照组无显著差异(P0.05),后3周内Ⅰ组和Ⅳ组差异显著(P0.05);第1、3、4周内,Ⅰ组和Ⅳ组四碘甲状腺原氨酸(T4)含量差异显著(P0.05),第2周内无显著差异,Ⅱ组和Ⅲ组差异均不显著(P0.05)。此外,不同组间的差异显著性随注射剂量不同而不同。     

关节炎大鼠脊髓背角降钙素基因相关肽和P物质的变化及针刺效应

将行为学实验与免疫组化ＬＳＡＢ技术结合，观察了大鼠在佐剂性关节炎发生发展中及针刺治疗时，脊髓背角降钙素基因相关肽（ＣＧＲＰ）和Ｐ物质（ＳＰ）的动态变化。结果表明，正常大鼠ＣＧＲＰ主要分布于脊髓背角Ⅰ、Ⅱ、Ⅴ、Ⅹ层和利骚厄氏束，ＳＰ主要分布于脊髓背角浅层。注入佐剂后第２天形成急性关节炎时，背角浅层和灰质后联合中ＣＧＲＰ免疫活性物质（ＣＧＲＰ－ＬＩ）和ＳＰ免疫活性物质（ＳＰ－ＬＩ）有所增加；第１４天发展为多发性关节炎时进一步明显增加，而且在灰质后联合中可见ＣＧＲＰ－ＬＩ长纤维；第２８天后随佐剂性关节炎的逐渐恢复而恢复。电针双侧环跳穴可减轻佐剂性关节炎大鼠的自发痛和痛觉过敏，并可预防多发性关节炎的发生，同时可见ＣＧＲＰ－ＬＩ和ＳＰ－ＬＩ增加的反应减弱。结果提示，佐剂性关节炎大鼠脊髓背角ＣＧＲＰ和ＳＰ的变化与关节炎的发生发展密切相关     

阿奇霉素对弓形虫病大鼠肝细胞周期和细胞凋亡及NO水平的影响

为了研究阿奇霉素对弓形虫病大鼠肝细胞周期及细胞凋亡及血清 NO水平的影响。用3 0只成年雄性 SD大鼠 ,随机分为感染组、治疗组和空白对照组 ,每组各 10只。感染组每只腹腔注射 2× 10 5/ m L 活的纯化弓形虫速殖子悬液 2m L。治疗组每只腹注同上剂量纯化弓形虫速殖子悬液后 ,每只每天喂服阿奇霉素 2 0 0 m g/ kg体重治疗 ,连用 7d。空白对照组每只腹注生理盐水 2 m L。 9周后解剖所有的大鼠 ,取肝组织制成单细胞悬液 ,应用流式细胞仪检测其细胞周期及细胞凋亡率。同时应用硝酸还原酶法测定各组大鼠血清 NO水平。结果表明 :感染组大鼠肝细胞凋亡率 ( 10 .3 0± 2 .62 ) %显著高于空白对照组大鼠肝细胞凋亡率 ( 9.2 3± 3 .0 3 ) % ( P<0 .0 5 )。治疗组大鼠肝细胞凋亡率 ( 9.73±3 .73 ) %明显低于感染组大鼠肝细胞凋亡率( 10 .3 0± 2 .62 ) % ( P <0 .0 5 )。治疗组大鼠肝细胞凋亡率与空白对照组大鼠肝细胞凋亡率相比较 ,无显著性差异 ( P >0 .0 5 )。肝细胞周期中 S期肝细胞比例感染组较治疗组低 ( P <0 .0 5 ) ,而 G1 期比例二者相反。治疗组与空白对照组比较细胞周期无显著性差异 ( P >0 .0 5 )。同时 ,感染组大鼠血清 NO平均水平为 ( 10 3 .2 6± 3 7.14 )μm ol/ L,治疗组大鼠血清 NO平均为 ( 85     

大豆异黄酮对肥胖大鼠肠道瘦素介导Janus激酶/信号转导及转录激活因子信号转导通路的影响

本试验旨在研究大豆异黄酮(SIF)对肥胖大鼠肠道瘦素介导Janus激酶(JAK)/信号转导及转录激活因子(STAT)信号转导通路的调控作用,探讨SIF对肥胖大鼠的干预机制。选取80只5周龄SD雄性大鼠,适应环境1周后,随机分为基础饲粮组(12只)和高脂饲粮组(68只),分别饲喂基础饲粮和高脂饲粮,饲喂8周后高脂饲粮组大鼠成功建立食源型肥胖大鼠模型。将40只肥胖大鼠随机分为SIF干预低、中、高剂量组和肥胖对照组,每组10只。低、中、高剂量组大鼠分别灌胃50、150、450 mg/kg BW的SIF提取物,基础饲粮组和肥胖对照组灌胃不含SIF提取物的溶媒剂。SIF连续干预肥胖大鼠5周,监测大鼠体重,并采用免疫组织化学链霉亲和素-生物素复合物(SABC)染色法研究大鼠肠道中长型瘦素受体(OB-Rb)、Janus激酶2(JAK2)、磷酸化的信号转导与转录激活因子3(p-STAT3)、细胞因子信号3抑制因子(SOCS3)和神经肽Y(NPY)的分布和表达。结果显示:试验各时期基础饲粮组大鼠体重均极显著低于肥胖对照组(P0.01)。SIF干预5周后,与肥胖对照组相比,各SIF干预组大鼠体重均下降,并表现出剂量依赖性,其中中、高剂量组极显著低于肥胖对照组(P0.01)。各组大鼠OB-Rb、JAK2、p-STAT3、SOCS3和NPY在十二指肠、空肠、回肠、结肠和直肠均有表达;同基础饲粮组相比,肥胖对照组大鼠上述5种因子在各肠段的表达量均显著降低(P0.05);SIF干预组中OBRb、JAK2、p-STAT3和NPY的表达量在各肠段均较肥胖对照组增多,总体呈现剂量依赖性。由此得出,SIF可通过增加肠道中OB-Rb的表达,激活JAK,加速STAT的磷酸化,改善能量代谢,减弱肥胖大鼠瘦素抵抗状态,来起到减重作用。     

苜蓿皂苷对大鼠肝脏及肝脏细胞低密度脂蛋白受体、三磷酸腺苷结合盒转运体mRNA表达的影响

本试验旨在研究苜蓿皂苷对大鼠肝脏及大鼠肝脏细胞(BRL细胞)胆固醇清除和转运途径中关键基因低密度脂蛋白受体(LDLR)、三磷酸腺苷结合盒转运体G5(ABCG5)、三磷酸腺苷结合盒转运体G8(ABCG8)mRNA表达量的影响,从个体和细胞水平初步探讨苜蓿皂苷调控胆固醇清除和转运的分子机制。采用高脂饲粮建立大鼠高脂模型,测定苜蓿皂苷对正常、高脂大鼠血清指标[总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)含量]和肝脏LDLR、ABCG5、ABCG8 mRNA表达量的影响;采用高糖DMEM培养液建立BRL细胞脂变模型,测定苜蓿皂苷浓度对BRL细胞活性的影响,测定苜蓿皂苷对正常、脂变细胞LDLR、ABCG5、ABCG8 mRNA表达量的影响。结果表明:1)苜蓿皂苷显著降低高脂大鼠血清中TG、TC和LDL-C的含量(P0.05);2)苜蓿皂苷显著上调正常大鼠肝脏LDLR、ABCG5、ABCG8及高脂大鼠ABCG5、ABCG8 mRNA表达量(P0.05);3)添加200、250μg/m L苜蓿皂苷显著提高了BRL细胞的活性(P0.05);4)苜蓿皂苷显著上调正常BRL细胞LDLR、ABCG5、ABCG8 mRNA表达量(P0.05),而对脂变BRL细胞各基因mRNA表达量无显著影响(P0.05)。结果提示,苜蓿皂苷可通过调控LDLR、ABCG5、ABCG8 mRNA的表达来增加肝细胞内胆固醇的清除和转运,从而降低机体胆固醇的含量。