不同比例虫草培养基混合料对SPF级Wistar大鼠主要脏器重量及其系数的影响

为探讨不同比例的虫草培养基混合料对SPF级Wistar大鼠主要脏器重量及脏器系数的影响，用电子天平测定3组动物的体重、心、肝、脾、肺、肾、肾上腺、睾丸、卵巢和胃的重量，并计算其脏器系数。结果表明，不同比例组的同性别Wistar大鼠，其体重之间不存在显著差异；低比例组雄性Wistar大鼠心脏、肺脏和睾丸，雌性Wistar大鼠肺脏的重量显著或极显著高〖JP2〗于对照组、高比例组；低比例组雄性Wistar大鼠心脏、肺脏、肾脏和睾丸，雌性Wistar大鼠心脏、肝脏、肺脏、肾脏和胃的脏器系数显著或极显著高于对照组、高比例组；低、高比例组Wistar雄鼠和高比例组Wistar雌鼠的肾上腺重量及其系数均显著低于对照组。可见，适当比例的虫草培养基可以作为啮齿类试验动物的添加料，但是否适用于饲喂其它动物还有待于进一步的试验研究。     

Strain differences in morphometrical characteristics of rat kidneys

To clarify the strain differences in the morphology of the rat kidneys, we investigated the morphometrical characteristics of the kidneys of Slc:Wistar, Slc:SD, and F344/NSlc rats. The diameter of the renal corpuscles in female F344/N rats is smaller than that in female Wistar rats. Although sex differences (males>females) were shown in SD and F344/N rats, no effects of castration were detected in any of the groups. Strain-dependent differences in the percentage of renal corpuscles with a cuboidal parietal layer were found in both male and female groups. The highest percentage of them was noted in male Wistar rats. Effects of castration were observed in female Wistar and male F344/N rats, and the values after castration were significantly higher than those in the intact animals. As for the number of proximal convoluted tubular nuclei, no strain differences were detected in either the male or female groups. Although a sex difference was found in SD rats (female>male), no effects of castration were detected in any of the groups. In female F344/N rats, numerous numbers of PAS-positive granules, which were observed in the proximal convoluted and straight tubular epithelia, were noted. Orchiectomy induced an increase of these granules in male SD and F344/N rats, but ovariectomy showed no effects on them in any strains. This is the first study to clarify the strain differences in the morphological characteristics of the kidneys in ordinary rat strains.     

Mucinous Bronchiolar Carcinoma of the Rat Lung A Case Report

A rare tumour—the diffuse form of mucinous bronchiolar carcinoma involving the entire left lung was seen in a 23 month old female rat that had been given 2,2-dinitrobiphenyl orally. The neoplastic lesion was characterized by many honey-combed spaces lined by tall, mucus-secreting columnar cells and filled with abundant mucus.     

Reproductive traits of the Ryukyu long-furred rat (Diplothrix legata) on Okinawa-jima Island

The Ryukyu long-furred rat, Diplothrix legata, is a large rodent distributed only on Amami-ohshima Island, Tokuno-shima Island and Okinawa-jima Island, Japan. This animal is endangered as a result of deforestation, predation by introduced carnivores and mortality caused by vehicles. We performed theriogenological examinations of 32 male and 25 female Ryukyu long-furred rats carcasses collected from wild populations on northern Okinawa-jima Island from December 2005 to September 2013. Adult males had remarkably large preputial glands. Seminiferous diameter of adult was significantly small (136 ± 28 µm, n=8) from April to August. Numerous spermatozoa were observed from September through February, and seminiferous diameter was significantly large (216 ± 27 µm, n=12) during this time in adults; testes length changed in a similar pattern. These findings indicate that the mating season may occur from September through February. Size (body length) at sexual maturity was estimated to be >560 mm in both sexes. From observation of corpora lutea and placental scars, litter size was estimated to range from 2 to 12 (average=6, n=4). These results provide fundamental knowledge that will be beneficial for in situ and ex situ conservation of this rare species.     

Hematology and clinical chemistry values in pregnant Wistar Hannover rats compared with nonmated controls

BACKGROUND: The Wistar Hannover rat has been considered as an alternative animal model to the Sprague-Dawley rat in the safety evaluation of candidate pharmaceuticals for potential reproductive and developmental toxicity. Hematology and clinical chemistry results may provide useful evidence of maternal toxicity in the absence of fetal effects. OBJECTIVE: The purpose of this study was to evaluate differences in routine laboratory values between nonmated and pregnant (near-term)Wistar Hannover rats during a control developmental study. METHODS: One hundred fifty pregnant female Wistar Hannover rats (Tac:Glx:WlfBR) were dosed orally once per day with distilled water from gestation days (GDs) 6 through 17. An additional 150 nonmated (nonpregnant) females used as age-matched controls were dosed from study days (SDs) 7 through 18. Blood samples were collected on GD 18 or 19 (SD 19 or 20) for routine hematology and plasma clinical chemistry tests. Reference intervals were established for pregnant and nonmated animals. RESULTS: On GD 18/19, pregnant rats had a lower RBC count, hemoglobin concentration, and HCT, and higher MCH, MCHC, reticulocyte percentage, and platelet, WBC, absolute reticulocyte, segmented neutrophil, lymphocyte, and monocyte counts compared with nonmated rats. Pregnant rats had lower albumin, glucose, urea, and chloride concentrations, lower creatine kinase and alkaline phosphatase activities, higher total bilirubin, cholesterol, triglyceride, calcium, phosphorus, and globulin concentrations, and higher ALT activity than nonmated rats. Serum triglyceride concentration was approximately fourfold higher in pregnant rats compared with nonmated controls. CONCLUSION: Differences in hematology and chemistry values in pregnant Wistar Hannover rats are similar to those in Sprague-Dawley rats and support use of the Wistar Hannover rat as an animal model in the assessment of maternal toxicity. Differences in laboratory values of pregnant rats should be considered when interpreting data following exposure to candidate pharmaceuticals.     

链脲佐菌素诱导1型糖尿病大鼠模型的影响因素探讨

通过注射链脲佐菌素(STZ)制作大鼠1型糖尿病模型,观察大鼠品系、给药剂量、给药次数对大鼠成模率、死亡率的影响,同时研究利用口服葡萄糖耐量试验(OGTT)判断大鼠糖尿病成模率的意义。随机取16只SD大鼠设置正常对照组。试验一:Wistar大鼠随机分为中剂量组(55 mg/kg,n=12)和高剂量组(65 mg/kg,n=12);试验二:SD大鼠一次性腹腔注射STZ(55 mg/kg,n=12),与1中的Wistar大鼠作对比;试验三:SD大鼠随机分为一次给药组(n=16)和两次给药组(n=16),注射剂量均为55 mg/kg,观察期间进行OGTT。结果表明,Wistar大鼠成模率和死亡率均高于SD大鼠;采用SD大鼠、中剂量给药和两次给药的方式可提高成模率,并降低死亡率;在有明确胰岛病理改变的模型组大鼠,其OGTT异常阳性率显著高于空腹血糖异常阳性率。用STZ诱导糖尿病模型是一种稳定可靠的方法。     

Study on Acute and Sub-chronic Toxicity of Wu Jin Granules

In order to evaluate the toxicity of Wu Jin granules for the guidance of clinical treatment, the acute and sub-chronic toxicity were assessed in KM mice and Wistar rats, respectively.The results of acute toxicity test suggested that the LD₅₀ of Wu Jin granules was >40 g/(kg·BW), maximal tolerance dose was 160 g/(kg·BW), equivalent to 80 times of clinical dosage.In sub-chronic toxicity test, the growth and general behavior of the animals appeared normal.Compared with the control group, weight gain and feed consumption of Wistar rats in the treatment groups had no significant difference (P>0.05).In high dose group, serum bilirubin (T-BIL), total protein (TP), albumin (ALB), urea nitrogen (BUN) and creatinine (CREA) of female Wistar rats, whereas CREA levels and liver index of male Wistar rats were significant difference (P<0.05), and the differences in other indexes were not significant (P>0.05); Hematological indexes, biochemical indexes of blood and organ index of Wistar rats in low dose group and medium dose group were not significantly different compared to the control group (P>0.05).Pathological examination results showed that mild granular degeneration existed in liver of Wistar rats in high dose group, whereas appeared clear and normal organizational structure of liver in Wistar rats in other groups.Wu Jin granules could inhibit intake of free bilirubin and hepatic synthesis protein in high dosage, whereas this results were not observed in other groups.Thus, the Wu Jin granules were safe in clinical treatment.     

乌锦颗粒剂的急性毒性与亚慢性毒性试验研究

本研究旨在评价乌锦颗粒剂的毒性,为临床安全用药提供理论依据。试验分别以昆明小鼠和Wistar大鼠为研究对象,进行急性毒性试验和亚慢性毒性试验研究。急性毒性试验结果显示,乌锦颗粒剂的半数致死量(LD₅₀)>40 g/kg体重,最大给药量为160 g/kg体重,相当于临床用药量的80倍;在亚慢性毒性试验中,动物一般情况正常,试验组Wistar大鼠增重和饲料消耗量与对照组相比无显著差异(P>0.05);与对照组相比,高剂量组中雌鼠血清胆红素(T-BIL)、总蛋白(TP)、白蛋白(ALB)、尿素氮(BUN)和肌酐(CREA)及雄鼠CREA和肝脏指数均有显著差异(P<0.05),而其他指标与对照组相比差异均不显著(P>0.05);低剂量组和中剂量组Wistar大鼠血常规、血液生化指标和脏器指数与对照组相比差异均不显著(P>0.05);病理学检查发现高剂量组Wistar大鼠肝脏出现轻微颗粒变性,其他组Wistar大鼠组织结构清晰正常。结果表明,高剂量的乌锦颗粒剂能抑制肝脏对游离胆红素的摄入及蛋白质的合成;低剂量和中剂量乌锦颗粒剂此作用不明显。综合分析,乌锦颗粒剂临床用药是安全的。     

Gender differences in morphometric properties of muscle fibres measured on cross-sections of rat hindlimb muscles

The study was aimed at demonstrating gender differences in the numbers, diameters and cross-section areas of muscle fibres for three hindlimb skeletal muscles responsible for locomotion and maintenance of body posture: soleus, tibialis anterior and flexor digitorum brevis in rats. The experiments were performed on five 6-month-old male and female Wistar rats. In both genders, all studied muscles of the right and left hindlimbs were isolated from surrounding tissues and excised for further procedures. The muscle transverse cross-sections taken from the muscle mid-belly were analysed. Following staining of reticular fibres by silver impregnation, the numbers, diameters and cross-section areas of muscle fibres were determined from microscopic images of muscle sections. The body mass of male rats was 80% higher than that of females. In addition, the muscle mass and the cross-section area were 53-82 and 26-45% higher in males, respectively. The number of muscle fibres was 11-42% higher in males than in females whereas the fibre diameters were 7-29% higher in males. The most conspicuous differences between males and females were found with respect to tibialis anterior, whereas the smallest differences were evident in soleus. The present study revealed that the gender morphometric differences in the studied rat hindlimb muscles were mainly owing to differences in number and size of muscle fibres and that the difference in muscle mass could be explained mainly from higher number of muscle fibres in males and to smaller degree from their larger diameters.     

二吡啶除草剂敌草快与肾上腺皮质激素引起胎鼠动脉管收缩的作用研究

本文研究了敌草快和肾上腺皮质激素对胎鼠动脉管的收缩作用。取妊娠19、20、21 d的大鼠,各随机分成2组。试验组皮下注射7 mg/kg敌草快,观察胎鼠动脉管收缩情况;取妊娠19 d大鼠,随机分成4组,试验1组未切除肾上腺,2、3组切除肾上腺。1、3组皮下注射7 mg/kg敌草快,第2组和对照组注射生理盐水,观察胎鼠动脉管收缩情况,并且测定母鼠血浆中肾上腺皮质激素的浓度;取妊娠19、20、21 d大鼠,各随机分成2组,试验组皮下注射40 mg/kg肾上腺皮质激素,观察胎鼠动脉管收缩情况,另用80 mg/kg肾上腺皮质激素,重复上述操作。结果表明:敌草快和肾上腺皮质激素对妊娠末期胎鼠动脉管具有收缩作用,且引起收缩的临界期均在胎龄19￣20 d。     

子宫内膜异位症大鼠模型复制

取Wistar大鼠30只,用手术移植的 方法把自体子宫内膜组织2块分别移植到壁 腹膜与子宫系膜处,建立子宫内膜异位症大 鼠模型。术后4周,再次开腹,观察异位内膜 的存活情况、与周围组织的粘连程度及病理 学变化。结果发现腹膜和子宫系膜处移植内 膜的成活率及病灶的体积差异无显著性(P >0.05),腹膜处病灶与周围组织的粘连程度 显著轻于子宫系膜处病灶(P<0.01),移植 物外观呈囊状,表面有血管,光镜下观察见子 宫内膜细胞、间质细胞、腺体和血管,与正常 在位内膜相比腺体减少。该模型复制方法简 便,成功率高,是研究子宫内膜异位症较理想 的动物模型。     

不同比例虫草培养基混合料对SPF级Wistar大鼠血液生化指标的影响

为了探讨不同比例的虫草培养基混合料对SPF级Wistar大鼠血液生化指标的影响， 收集3组共60只Wistar大鼠的18项血液生化指标进行统计分析。结果发现，试验组Wistar大鼠的血红蛋白、嗜酸性细胞的水平均显著低于对照组；试验组雄性Wistar大鼠的胆固醇、甘油三酯水平均显著低于对照组，尿素氮和血糖显著高于对照组；试验组雌性Wistar大鼠的谷丙转氨酶和谷草转氨酶水平均显著高于对照组，而胆固醇和甘油三酯水平均显著低于对照组；其他指标各组间和不同性别间均无显著差异。研究结果表明，饲喂不同比例的虫草培养基混合料，可使SPF级Wistar大鼠的部分血液生化指标发生明显改变。      

Anophthalmia and retinal degeneration associated with stenosis of the optic foramen in Fischer 344 rats

Bilateral anophthalmia was discovered in a male rat (No. 1) and unilateral anophthalmia was found in the left eye of two female rats (Nos. 2 and 3) derived from a Fischer 344 inbred colony. One male rat (No. 4), a littermate of No. 3, had externally normal eyes, but his left eye had severe retinal atrophy, which was detected by ophthalmoscopy. The eyelids in both eyes of No. 1 and in the left eyes of Nos. 2 and 3 were present. Radiography of the skull revealed small optic foramina on both sides of No. 1 and on the affected side of Nos. 2, 3, and 4. Histologically, both globes and optic nerves (ONs) of No. 1 and the left globe and ONs of Nos. 2 and 3 were completely missing. Diffuse retinal degeneration in the left globe and axonal degeneration in the left ON and the right optic tract were observed in No. 4. Dysplasia of the sphenoid bone associated with stenosis of the optic foramen was detected on the affected side of all rats. Thus, ON aplasia in anophthalmic rats and atrophic ON in a rat with retinal degeneration seem to be closely related to stenosis of the optic foramen.     

Correlations between presence of spontaneous lesions of the pituitary (adenohypophysis) and plasma prolactin concentration in aged Wistar rats.

The predictive value of elevated plasma prolactin concentrations for the presence of spontaneous pituitary lesions was studied in 40 male and 38 female Wistar (Cpb:WU) rats, all 30 months old. The pituitaries were examined light microscopically and stained for prolactin using immunohistochemical methods. Plasma prolactin concentrations were measured by radioimmunoassay. Pituitary lesions were classified on the basis of their morphology in hematoxylin and eosin-stained sections as foci of hypertrophic or hyperplastic cells and hemorrhagic, pleomorphic, or spongiocytic adenomas; no carcinomas were found. There were significantly (P = 0.001) more female than male rats with pituitary adenomas (58% females, 33% males) or without any pituitary lesions (21% females, 5% males); however, there were less female (21%) than male rats (63%) with foci of hyperplastic and/or hypertrophic cells but no adenomas in the pituitary (P = 0.001). Elevation of plasma prolactin concentration above the upper 99th percentile value in age-matched rats without lesions was predictive, but not conclusively, of the presence of pituitary hemorrhagic adenomas in both sexes. It was, however, not predictive of the presence of foci of hypertrophic or hyperplastic cells. Elevation of plasma prolactin concentration above 10 ng/ml in male and 60 ng/ml in female rats was conclusive for the presence of hemorrhagic adenomas. Using multivariate analysis, significant positive correlations (P less than 0.01) were found between plasma prolactin concentration and presence and size of hemorrhagic adenomas and their prolactin staining intensity (correlation coefficients between 0.392 and 0.652). Foci of hyperplastic cells stained positively for prolactin, whereas hypertrophic cell foci and pleomorphic and spongiocytic adenomas did not stain for prolactin. There were no correlations (coefficients of less than +/- 0.189) between plasma prolactin concentration and the presence of hypertrophic or hyperplastic cell foci and pleomorphic or spongiocytic adenomas in the pituitary. The morphologic criteria developed to distinguish spontaneous hypertrophic, hyperplastic, and neoplastic lesions of the rat pituitary corresponded well with their prolactin immunoreactivity and/or ability to elevate plasma prolactin concentration. These criteria constitute a biologically meaningful classification system for these rat pituitary lesions.     

Androgen- and estrogen-dependent sex differences in host resistance to Strongyloides venezuelensis infection in Wistar rats

The effects of male and female sex hormones on the protective capacity of Wistar rats against infection with Strongyloides venezuelensis were investigated. Male rats were more susceptible than females in terms of worm recovery from the lungs. Orchidectomy of male animals significantly reduced the plasma testosterone concentration and increased host resistance to the migratory stages of S. venezuelensis larvae. In contrast, ovariectomy of female animals significantly decreased host resistance in association with a significant reduction of estrogen levels. To examine the direct effect of sex hormones, exogenous testosterone and estrogen were implanted into animals. Susceptibility significantly increased or decreased in ovariectomized females given testosterone or estrogen, respectively. These results suggest that male and female sex hormones are important in the down- and up-regulation of host resistance against S. venezuelensis in Wistar rats.     

Background data of 2-year-old male and female F344 gpt delta rats

Although gpt delta rats, as reporter gene-transgenic rats, were originally developed for in vivo mutation assays, they have also been used to evaluate chemical carcinogenesis and comprehensive toxicity. Therefore, it is necessary to accumulate background data on carcinogenicity and general toxicity in gpt delta rats. Here, we investigated the background data of 110-week-old male and female F344 gpt delta rats and wild-type rats. There was no effect of reporter gene transfection on animal survival rates and body weights during the experiment. The relative weight of male gpt delta rat adrenals was significantly higher than that of wild-type rats, possibly due to the higher incidence of pheochromocytoma. There were no intergenotype differences in the incidence of nonneoplastic lesions in both sexes, including chronic progressive nephropathy and focus of cellular alteration in the liver, which had a higher incidence in both genotypes. Additionally, the significantly higher incidence of adrenal pheochromocytoma in male gpt delta rats than that in wild-type rats was likely incidental because of the lack of differences in the incidences of preneoplastic (male and female) and neoplastic (female) adrenal lesions in both genotypes. Other neoplastic lesions in both sexes showed no intergenotype differences in incidence rates, although large granular lymphocytic leukemia in the spleen and Leydig cell tumors in the testes of males showed higher incidence rates. Overall, there were no effects of reporter gene transfection on the spectrum of spontaneous lesions in F344 gpt delta rats, thus supporting their applicability in evaluating chemical toxicity and carcinogenicity.     

The influence of sex and gonadectomy on hepatic and brain fatty acid composition,lipogenesis and β‐oxidation

The aim of this study was to investigate the influence of sex and castration of rats on liver and brain fatty acid profile and liver mRNA expression of genes involved in lipogenesis and β‐oxidation. Castration significantly increased body weight and liver index and decreased serum triglyceride content in the female rats. The fatty acid composition of the liver tissue was influenced by sex and castration. Male rats had higher content of C16:0, C18:1n7, C18:2n6 and C22:5n3, while female rats had higher content of C18:0, C20:4n6 and C22:6n3. Castration of male rats decreased differences caused by sex for C18:2n6, C20:4n6 and C22:6n3. Values for C16:1n7 were higher in the castrated male rats in comparison with all other groups. Liver phospholipids showed a distribution of fatty acids similar to the total lipids. Brain total lipids and phospholipids were not influenced by sex or castration. Castration increased ?6D gene expression in both the sexes, while ?5D and ?9D increased in females and males respectively. Gonadectomy increased expression of the FASN gene in the females and decreased CPT1 and ACOX1 gene expression in the liver tissue of male rats. The observed results of lipid peroxidation, measured by TBARS, were the lowest in the intact females in comparison with all other groups. In conclusion, sex strongly influences both SFA and PUFA in liver tissue, and castration decreases these differences only for PUFA. Castration also influences the expression of the genes involved in lipid metabolism differently in male and female rats, with an increase in lipogenic genes in female rats and a decrease in key genes for mitochondrial and peroxisomal β‐oxidation in male rats.     

Lewis rats are not susceptible to oral infection with Mycobacterium avium subsp. paratuberculosis

Pathogenesis studies of Mycobacterium avium subsp. paratuberculosis infection in ruminants are hampered by the long incubation time of the disease. A laboratory animal model with a shorter incubation time would facilitate research in this field. Although small rodents are usually considered to be resistant to M.a. paratuberculosis infection, several susceptible murine strains have been found. To our knowledge, there are no detailed reports with regard to susceptibility in rats. The Lewis rat is a valuable model for inflammatory bowel disease studies as well as autoimmune diseases involving mycobacteria as inducing agents. In this study Lewis rats were used to investigate their potential as a small laboratory animal model for paratuberculosis.In total 28 female Lewis rats were orally inoculated with M.a. paratuberculosis. The rats were first inoculated at 3 weeks of age, and 12 more inoculations followed in increasing intervals during the 3 months to follow. Eight control rats received a sham inoculation. Over 9 months, two rats from each group were sacrificed at regular intervals and immunological and histopathological examinations were performed on the gastrointestinal tract, the liver and the spleen.None of the rats developed lesions which were indicative of mycobacterial infection as determined by histology with HE and Ziehl-Neelsen staining. The bacteria could not be recultured from samples taken from the gut, the liver or the spleen. The immunological tests however, showed that bacteria had entered via the intestinal tract. From this study it appears that Lewis rats are resistant to oral inoculation with M. a. paratuberculosis, and not suitable as a model to study the immunopathogenesis of paratuberculosis as it occurs in ruminants.     

Comparison of distal forelimb conformations between Japanese Black and Holstein-Friesian newborn calves

Flexural and hyperextension deformities are congenital problems in calves. We, therefore, aimed to investigate the distal limb conformation in 1 day- and 28-day-old female Holstein-Friesian (HF) calves (n=21), male Japanese Black (JB) calves (n=15), and female JB calves (n=15). The claw angle of the forelimb dorsal claw wall in a standing position and recorded other parameters, including body weight, withers height, circumference of forelimbs, and flexor tendon thickness in the forelimbs, were measured and compared these between the three groups. At 1 day old, the mean claw angles were 51.1° in female HF calves, 47.0° in male JB calves, and 41.8° in female JB calves; the 95% confidence intervals (CIs) of the claw angles showed large distributions in all three groups. One female HF and one male JB calves showed mild flexural deformity, whereas four JB calves showed hyperextension deformity. At 28 days old, the mean claw angles were 51.7° in female HF calves, 51.2° in male JB calves, and 48.4° in female JB calves; the 95% CIs of the claw angles showed smaller distributions than those at 1 day old in all groups. For all groups, the limb deformities had improved without treatment at 28 days old. As a feature of the breed, female JB calves were apt to show hyperextended deformities inversely proportional to the body weight. These limb deformities healed spontaneously and were thought to be physiological.