肾小球硬化大鼠模型的实验研究

为了建立一接近人类肾小球硬化病理特征、制作周期短、稳定性重复性良好的动物模型,以供新药研究之用,对健康雄性SD大鼠行左侧肾切除合并阿霉素双次注射尾静脉的方法建立肾小球硬化动物模型.正常组则行假手术及予等量生理盐水尾静脉注射.于第0,2,4,6,8周留取24h尿液测定尿蛋白含量;第8周末取血检测血生化指标,单侧肾切除合并阿霉素双次尾静脉注射的肾小球硬化模型大鼠的24h蛋白尿、血脂都较正常组明显升高.该模型病理特征与人类肾小球硬化相似,其建立为治疗肾小球硬化的新药开发奠定了实验基础.     

动脉粥样硬化SD大鼠模型的建立

目的建立适合于心血管疾病研究的SD大鼠动脉粥样硬化模型。方法110只雄性SD大鼠随机分为两组,每组55只,分别为实验组和对照组,对照组喂养普通饲料,实验组喂养高脂饲料和0.2%丙基硫氧嘧啶。6个月后对所有大鼠行超声检查升主动脉、主动脉弓、降主动脉、胸主动脉、腹主动脉,超声检查后处死大鼠行病理学检查,观察主动脉管壁病理改变。结果对照组SD大鼠未出现明显病变,动脉粥样硬化组大鼠6个月后超声及病理可以检测到动脉粥样硬化斑块。结论成功建立快速简便的SD大鼠动脉粥样硬化模型,可用于动脉粥样硬化的研究。     

硫代乙酰胺诱导大鼠肝纤维化模型的制备

目的:建立稳定高效的硫代乙酰胺(thioacetamide,TAA)大鼠肝纤维化模型,分析大鼠肝脏病理纤维化分级与血清检测物指标,为临床提供适用的监测手段及理论依据。方法:选取SD雄性大鼠48只,随机分为4组,即对照组(12只)、模型-Ⅰ组(12只)、模型-Ⅱ组(12只)和模型-Ⅲ组(12只)。根据大鼠体重,采用腹腔注射TAA诱导肝纤维化。按实验给定时间给药,在不同时间段内测定谷草转氨酶(AST)和谷丙转氨酶(ALT)血清浓度,并进行肝脏病理组织学检查。结果:模型-Ⅰ组大鼠死亡率为25.00%(3/12)、肝纤维化形成率为75.00%(9/12);模型-Ⅱ组大鼠死亡率为8.33%(1/12)、肝纤维化形成率为91.67%(11/12);模型-Ⅲ组肝纤维化形成率为83.33%(10/12)。各组AST和ALT血清浓度均升高,肝脏病理组织学检查发现肝组织病变。结论:本法病理组织学检查结果可靠,操作简便,适用于实验肝纤维化模型制备。     

痛风颗粒治疗痛风性关节炎的实验研究

［摘要］目的观察痛风颗粒对急性发作期痛风性关节炎大鼠的治疗作用，初步探讨其作用机制。方法用痛风颗粒治疗尿酸钠诱导的急性痛风性关节炎模型大鼠，并设有空白对照组、模型对照组、西药对照组，观察治疗前后受试关节周径、关节腔组织和血浆中前列腺素E2（PGE2）含量、关节腔积液中白细胞数量的变化。结果用药后，模型大鼠受试关节周径明显缩小，肿胀率下降（P＜0.05，P＜0.01），关节周围组织和血浆PGE2含量及关节腔积液中白细胞数量下降（P＜0.05，P＜0.01）。结论痛风颗粒可以有效抑制急性痛风性关节炎模型大鼠关节肿胀。其作用机制可能是通过抑制白细胞向炎症局部的聚集和炎症递质PGE2的分泌。     

Effect of Fluoxetine on an Experimental Model of Diabetes-induced Neuropathic Pain Perception in the Rat

The aim of the present study was to study the effect of chronic treatment (9 weeks) of fluoxetine (20 mg/kg p.o.) a selective serotonin reuptake inhibitor on blood glucose level and in prevention of diabetic neuropathic pain perception. Evaluation of diabetic neuropathy was performed after 9 weeks of single injection of streptozotocin (70 mg/kg i.v.) in rats. Blood glucose level, glycated haemoglobin, grip strength, pain sensitivity and threshold in diabetic rats were measured at the end of 9 weeks. The results of the present study indicate that the 9 weeks treatment of fluoxetine demonstrates hypoglycemic effect; it marked decreases the blood glucose level in diabetic treated animals. There was also decrease in the grip strength in diabetic rat indicates to induction of neuropathy or nerve damage. Fluoxetine increase the grip strength of diabetic rats. There was also found loss of pain perception in diabetes rats which measured using hot plate and tail flick methods. Fluoxetine increases the licking time and withdrawal latency in hot plate and tail flick test respectively indicates the presence of pain perception and prevention of nerve damage demonstrates its protective effect in diabetic neuropathy. Our study concludes the chronic treatment of fluoxetine significantly decreases the glycemic level as well as it protected from the development of diabetic neuropathy.     

重组甘精胰岛素对糖尿病大鼠模型代谢影响的实验研究

目的:研究长效胰岛素重组甘精胰岛素对糖尿病大鼠代谢紊乱的调节作用。方法:将糖尿病模型大鼠40只随机分为5组,每组8只,雌雄各半。分为正常对照组、模型对照组、重组胰岛素注射液大、中、小剂量组和阳性对照组。主要观察精神、进食、体重等指标,测定试验大鼠血糖、糖化血红蛋白定量,血清中TG、TC、TP、Alb含量及血清中SOD、XOD酶活性、MDA含量。结果:重组甘精胰岛素注射液治疗组及阳性对照组大鼠平均体重增加,治疗组及阳性对照组大鼠血糖浓度较模型组血糖浓度均有降低(P0.05);血清甘油三酯的含量降低(P0.05),总胆固醇降低(P0.05),增加血清总蛋白水平、血清白蛋白水平,升高血清SOD的活性(P0.05),降低XOD的活性(P0.05),降低MDA的含量(P0.05);降低糖尿病大鼠血尿素氮的含量(P0.05);降低糖尿病大鼠糖化血红蛋白的含量(P0.05)。结论:重组甘精胰岛素对糖尿病大鼠的代谢紊乱有调节作用。     

大鼠离体肝脏灌流系统的建立

目的：建立大鼠离体肝动脉／门静脉灌流系统的实验方法。方法：雌性Wistar大鼠麻醉状态下,肝动脉、门静脉和肝静脉插管;经肝动脉冲净残留血液,灌流状态下游离肝脏;定量蠕动泵调节肝动脉或门静脉的Krebs—Henseleit平衡液（或加等渗葡聚糖）的灌流流速,泰盟BL-420S生物机能实验系统监测肝动脉或门静脉的压力变化,采用Prism-4非线型可变斜率回归获得“有或无胶体渗透压”KH液灌流的流速-压力曲线及方程式,计算半效流速及其95％的可信限。结果：无胶体渗透压灌流状态下的肝脏系数无差别,肝动脉的半效流速为2217（95％CI1209～4068）μl·min^－1,对数流速-压力直线方程为Y=142．4x＋706．9;门静脉半效流速为3791（95％CI3549～4049）μl·min^－1,对数流速-压力直线方程为Y：479．6X＋5034。等效胶体渗透压灌流状态下的肝脏系数无差别,肝动脉半效流速为3754（95％CI3175～4440）μl·min^－1,对数流速-压力直线方程为Y=133．5X-719．0;门静脉半效流速为6018（95％CI5565—6508）μl·min^－1,对数流速-压力直线回归方程为Y：538．3X4-4704。半效流速接近正常大鼠生理平均值,各半效流速95％可信限涵盖大鼠正常生理状态的变化范围。有或无胶体渗透压灌流状态之间总体无差别。结论：在恒流测压模式下,等渗灌流大鼠离体肝动脉和门静脉灌流系统的视窗时程长、机能变化稳定、操作流程简便,为认识肝动脉和门静脉离体舒缩机制奠定了基础。     

Inducible Aldehyde Dehydrogenases in the Hepatic Cytosol of the Rat

Abstract Rats of the Wistar/Af/Han/Mol/(Han 67) strain have previously been shown to respond in a variable way to phenobarbital treatment, as far as the induction of aldehyde dehydrogenase activity is concerned ( Marselos 1976 ). This biochemical property is genetically determined and concerns the high-Km aldehyde dehydrogenase of the hepatic cytosol. In this study, administration of phenobarbital (1 mg/ml of drinking water, for 1 week) produces a uniform induction of aldehyde dehydrogenase in all rats, when measured with micromolar substrate concentration. The inducible low-Km enzyme of the cytosol is not genetically determined like the high-Km enzyme, and shows a wide specificity for aliphatic as well as for aromatic aldehydes. Despite the inducibility of the cytosolic enzymes, no alterations are found in the mitochondrial aldehyde dehydrogenase activities after phenobarbital treatment. The oxidation of D-glucuronolactone takes place only in the cytosol, and seems to be dependent on the low-Km aldehyde dehydrogenase. This is consistent with NMR studies, which showed that a very minimal amount of D-glucuronolactone is in aldehyde form under the measurement conditions usually applied. Further, the oxidation of D-glucuronolactone is also enhanced by phenobarbital in all rats without a genetic predisposition, and its dose-response curve is very similar to that of the low-Km aldehyde dehydrogenase.     

Optimal Experimental Design for Precise Estimation of the Parameters of the Axial Dispersion Model of Hepatic Elimination

The axial dispersion model of hepatic drug elimination is characterized by two dimensionless parameters, the dispersion number, D_N , and the efficiency number, R_N , corresponding to the relative dispersion of material on transit through the organ and the relative efficiency of elimination of drug by the organ, respectively. Optimal design theory was applied to the estimation of these two parameters based on changes in availability (F) of drug at steady state for the closed boundary condition model, with particular attention to variations in the fraction of drug unbound in the perfusate (fu_B ). Sensitivity analysis indicates that precision in parameter estimation is greatest when F is low and that correlation between R_N and D_N is high, which is desirable for parameter estimation, when D_N lies between 0.1 and 100. Optimal design points were obtained using D-optimization, taking into account the error variance model. If the error variance model is unknown, it is shown that choosing Poisson error model is reasonable. Furthermore, although not optimal, geometric spacing of fu_B values is often reasonable and definitively superior to a uniform spacing strategy. In practice, the range of fu_B available for selection may be limited by such practical considerations as assay sensitivity and acceptable concentration range of binding protein. Notwithstanding, optimal design theory provides a rational approach to precise parameter estimation.     

两种构建大鼠膀胱癌模型方法的比较研究

目的通过BBN喂饲和MNU膀胱灌注方法构建大鼠膀胱癌模型,比较两种实验方法的优缺点。方法BBN诱癌组大鼠使用0.05%BBN溶液连续喂养6周,后改用2%枸橼酸钠溶液作后续喂养22周,第28周为诱导的终点。MNU诱癌组大鼠行MNU膀胱灌注,每两周灌药一次,每次2mg/只,共4次,第10周为诱导的终点。比较两组大鼠的成瘤率和死亡率。结果BBN诱癌组30只大鼠喂养28周后存活16只,11只成瘤,病死率46.7%,存活大鼠成瘤率68.8%;MNU诱癌组30只大鼠第10周存活28只,25只成瘤,病死率6.7%,存活大鼠成瘤率89.3%。结论利用MNU行大鼠膀胱灌注的方法构建大鼠膀胱癌模型,具有成瘤时间短、成瘤率高、大鼠病死率低等特点,优于BBN喂饲大鼠成瘤的方法。     

己酮可可碱抗大鼠肝纤维化的实验研究

目的:已酮可可碱是一种甲基黄嘌呤血管扩张剂,观察其对综合因素诱导的大鼠肝纤维化的治疗效果,探讨其作用机理、方法:实验采用CCl4及高脂低胆碱及酒精饮食诱导,形成大鼠肝纤维化模型,然后分别给予口服已酮可可碱、秋水仙碱及蒸馏水对照治疗10周。治疗前后测定血ALT,纤维化指标IV型胶原,细胞因子肿瘤坏死因子-α的浓度,同时作肝脏病理检查。结果:口服已酮可可碱大鼠血清ALT、IV型胶原、肿瘤坏死因子-α浓度均低于对照组(P<0.05),病理结果表明已酮可可碱治疗后肝纤维化分级低于对照组(P<0.05),染色显示其胶原面积百分比下降,低于对照组(P<0.05)。结论:已酮可可碱能有效治疗及预防大鼠肝纤维化,是具有临床抗纤维化治疗潜力的药物。     

Semi-mechanistic Modelling of the Analgesic Effect of Gabapentin in the Formalin-Induced Rat Model of Experimental Pain

Purpose

The formalin-induced rat model of nociception involves moderate continuous pain. Formalin-induced pain results in a typical repetitive flinching behaviour, which displays a biphasic pattern characterised by peaks of pain. Here we described the time course of pain response and the analgesic effect of gabapentin using a semi-mechanistic modelling approach.

Methods

Male Sprague-Dawley rats received gabapentin (10–100 mg/kg) or placebo 1 h prior to the formalin injection, as per standard protocol. A reduction in the frequency of the second peak of flinching was used as a behavioural measure of gabapentin-mediated anti-nociception. The flinching response was modelled using a mono-exponential function to characterise the first peak and an indirect response model with a time variant synthesis rate for the second. PKPD modelling was performed using a population approach in NONMEM v.7.1.2.

Results

The time course of the biphasic response was adequately described by the proposed model, which included separate expressions for each phase. Gabapentin was found to reversibly decrease, but not suppress the flinching frequency of the second response peak only. The mean IC₅₀ estimate was 7,510 ng/ml, with relative standard error (RSE%) of 40%.

Conclusions

A compartmental, semi-mechanistic model provides the basis for further understanding of the formalin-induced flinching response and consequently to better characterisation of the properties of gabapentin, such as the potency in individual animals. Moreover, despite high exposure levels, model predictions show that gabapentin does not completely suppress behavioural response in the formalin-induced pain model.     

Evidence of Chemical Stimulation of Hepatic Metabolism by an Experimental Acetanilide (FOE 5043) Indirectly Mediating Reductions in Circulating Thyroid Hormone Levels in the Male Rat

N-(4-Fluorophenyl)-N-(1-methylethyl)-2-[[5-(trifluoromethyl)-1,3,4-thiadiazol-2-yl]oxy]acetamide(FOE 5043) is a new acetanilide-type herbicide undergoing regulatorytesting. Previous work in this laboratory suggested that FOE5043-induced reductions in serum thyroxine (T₄) levels weremediated via an extrathyroidal site of action. The possibilitythat the alterations in circulating T₄ levels were due to chemicalinduction of hepatic thyroid hormone metabolism was investigated.Treatment with FOE 5043 at a rate of 1000 ppm as a dietary admixturewas found to significantly increase the clearance of [¹²⁵I]T₄from the serum, suggesting an enhanced excretion of the hormone.In the liver, the activity of hepatic uridine glucuronosyl transferase,a major pathway of thyroid hormone biotransformation in therat, increased in a statistically significant and dose-dependentmanner; conversely, hepatic 5'-monodeiodinase activity trendeddownward with dose. Bile flow as well as the hepatic uptakeand biliary excretion of [¹²⁵I]T₄ were increased following exposureto FOE 5043. Thyroidal function, as measured by the dischargeof iodide ion in response to perchlorate, and pituitary function,as measured by the capacity of the pituitary to secrete thyrotropinin response to an exogenous challenge by hypothalamic thyrotropinreleasing hormone, were both unchanged from the controlled response.These data suggest that the functional status of the thyroidand pituitary glands has not been altered by treatment withFOE 5043 and that reductions in circulating levels of T₄ arebeing mediated indirectly through an increase in the biotransformationand excretion of thyroid hormone in the liver.     

一过性离体大鼠肝脏灌流模型的建立

目的利用UP-100通用灌流仪建立了一过性离体大鼠肝脏灌流模型。方法用Krebs-Henseleit碳酸氢盐缓冲液进行一过性离体大鼠肝脏灌流,在灌流时长90 min内通过检测AST、ALT和LDH的浓度,观察肝脏外观及胆汁流量,测定肝重变化,进行组织切片观察组织病理变化来评估离体灌流肝脏的损伤程度。结果 90 min灌流时长中,肝脏颜色质地正常,胆汁流量均匀,相应转氨酶释放量少,病理切片结果正常。结论离体大鼠肝脏在UP-100通用灌流仪90 min灌流过程中能保持较好的组织结构和肝脏功能,可用于离体肝脏的药物代谢研究。