Magnetic resonance imaging of hepatocellular carcinoma induced by diethylnitrosamine in Sprague-Dawley rats

Diethylnitrosamine (DENA) is able to induce various benign and malignant liver lesions in rats with a high success rate and a low mortality rate. It provides a more appropriate model that better simulates the various lesions occurring in humans than the usual model of tumor implantations. The aim of the present study was to evaluate MRI liver examination in Sprague-Dawley(SD) rats as a routine method to detect hepatocellular carcinoma (HCC) nodules induced by DENA and to follow up their growth. METHODS:Hepatic carcinogenesis was induced in 80 male SD rats using oral DENA solution. All animals were imaged for liver tumor detection with a 1.5 Tesla magnet (Siemens Sonata,Erlangen, Germany) using correspondence scan parameters and a radio-frequency knee coil. Macroscopic examinations were performed along the axial MRI sections to evaluate magnetic resonance imaging (MRI) findings, and histopathological assessment was also performed. RESULTS:No false negative results were obtained on MR images. Hepatic tumors in 72 rats were confirmed macro-scopically and 68 rats were detected by MRI till the 20th week. The smallest and the largest nodules detected by MRI were 2 mm and 37 mm in diameter respectively. The agreement rate of MRI with macroscopic observation was 39. 1% and 97. 4% respectively for 2 mm to 5 mm and more than 5 mm nodules. CONCLUSIONS:The hepatic tumor induced by DENA provides a more representative range of tumors for imaging diagnosis and interventional treatment. MRI is the best approach for scrutinizing pathological changes of rat livers in the period of observation.

Analysis of transcriptome sequencing of sciatic nerves in Sprague-Dawley rats of different ages

An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that may affect the biological function of peripheral nerves. Ten 1-week-old and ten 12-month-old healthy male Sprague-Dawley rats were divided into young（1 week old） and adult（12 months old） groups according to their ages. mRNA expression in the sciatic nerve was compared between young and adult rats using next-generation sequencing（NGS） and bioinformatics（n = 4/group）. The 18 groups of differentially expressed mRNA（DEmRNAs） were also tested by quantitative reverse transcription polymerase chain reaction（n = 6/group）. Results revealed that（1） compared with young rats, adult rats had 3608 groups of DEmRNAs. Of these, 2684 were groups of upregulated genes, and 924 were groups of downregulated genes. Their functions mainly involved cell viability, proliferation, differentiation, regeneration, and myelination.（2） The gene with the most obvious increase of all DEmRNAs in adult rats was Thrsp（log2 FC = 9.01, P 〈 0.05）, and the gene with the most obvious reduction was Col2 a1（log2 FC = -8.89, P 〈 0.05）.（3） Gene Ontology analysis showed that DEmRNAs were mainly concentrated in oligosaccharide binding, nucleotide-binding oligomerization domain containing one signaling pathway, and peptide-transporting ATPase activity.（4） Analysis using the Kyoto Encyclopedia of Genes and Genomes showed that, with increased age, DEmRNAs were mainly enriched in steroid biosynthesis, Staphylococcus aureus infection, and graft-versus-host disease.（5） Spearman＇s correlation coefficient method for evaluating NGS accuracy showed that the NGS results and quantitative reverse transcription polymerase chain reaction results were positively correlated（rs = 0.74, P 〈 0.05）. These findings confirm a difference in sciatic nerve gene expression between adult and young rats, suggesting that, in peripheral nerves, cells and the microenvironment change with age, thus influencing the function and repair of peripheral nerves.

Hormetic Effects of Yttrium on Male Sprague-Dawley Rats

To evaluate hormesis induced by Yttrium（Y） nitrate in male rats, Y was offered to F0 mother rats and F1 offspring at concentrations of 0, 20, 80, and320 ppm daily from gestational day （GD） 0 through postnatal day 70（PND70）.The F1 offspring were evaluated with respect to motor function,learning and memory, and histopathology.

不同周龄和性别的SPF级SD大鼠血液生理生化指标的测定与比较分析

目的探讨分析不同周龄和性别的SPF级SD大鼠血液生理生化指标。方法研究对象为SPF级SD大鼠80只,并随机将其分为4、12、24、48周龄4个实验组,每组内雌雄比例为1:1,所有SD大鼠均应用XFA6030型动物血液细胞分析仪对其血液生理指标展开分析,应用Beckman Coulter AU5800全自动生化分析仪对其血液生化指标展开分析。结果与12、24、48周龄SD大鼠相比较,4周龄的SD大鼠在WBC、RBC、HGB、HCT、MCV、MCH、MCHC、PLT、PCT、BA#、BA%几方面具有较大差异,P<0.05,且各项指标达到峰值的时间均为24周,在雌雄的性别差异中,4周龄SD大鼠BA%具有差异;12、24周龄SD大鼠WBC、RBC具有差异;24周龄SD大鼠BA%具有差异;48周龄SD大鼠MCH、PCT具有差异,且所有差异P值均<0.05;与12、24、48周龄SD大鼠相比较,4周龄的SD大鼠在AST、CHOL、TP、GLU、CRE、ALT、ALP、BUN、TG几方面具有较大差异,P<0.05,在雌雄的性别差异中,4周龄SD大鼠CRE、ALP见具有差异;12周龄SD大鼠AST、CHOL、BUN具有差异;12周龄以及24周龄SD大鼠ALP具有差异,且所有差异P值均<0.05。结论在性别相同但周龄不同的SD大鼠中,其血液生理生化指标存在统计学差异,同样的,在同周龄但不同性别的SD大鼠中亦存在差异。

Differences in action potential propagation speed and axon initial segment plasticity between neurons from Sprague-Dawley rats and C57BL/6 mice

Action potentials(APs)in neurons are generated at the axon initial segment(AIS).AP dynamics,including initiation and propagation,are intimately associated with neuronal excitability and neurotransmitter release kinetics.Most learning and memory studies at the single-neuron level have relied on the use of animal models,most notably rodents.Here,we studied AP initiation and propagation in cultured hippocampal neurons from Sprague-Dawley(SD)rats and C57BL/6(C57)mice with genetically encoded voltage indicator(GEVI)-based voltage imaging.Our data showed that APs traveled bidirectionally in neurons from both species;forward-propagating APs(fpAPs)had a different speed than backpropagating APs(bpAPs).Additionally,we observed distinct AP propagation characteristics in AISs emerging from the somatic envelope compared to those originating from dendrites.Compared with rat neurons,mouse neurons exhibited higher bpAP speed and lower fpAP speed,more distally located ankyrin G(AnkG)in AISs,and longer Nav1.2 lengths in AISs.Moreover,during AIS plasticity,AnkG and Nav1.2 showed distal shifts in location and shorter lengths of labeled AISs in rat neurons;in mouse neurons,however,they showed a longer AnkG-labeled length and more distal Nav1.2 location.Our findings suggest that hippocampal neurons in SD rats and C57 mice may have different AP propagation speeds,different AnkG and Nav1.2 patterns in the AIS,and different AIS plasticity properties,indicating that comparisons between these species must be carefully considered.

Analysis of Behaviour Pattern in Sprague-Dawley Rats Using Microwave Techniques

This communication presents a new method of detecting the behaviour pattern in Sprague-Dawley (SD) rats based on the measurement of the dielectric properties of blood plasma at microwave frequencies at different periods of time. The microwave measurements were performed by rectangular cavity perturbation method in the S-band of microwave frequency with the blood plasma collected from normal rats (Controls) as well as chemically induced rats (A&beta;). A change is observed in the dielectric properties of the A&beta;samples but not the controls samples at the extended period of time. This measurement technique is simple and the collection of blood from the rats is nonsurgical in nature. These results prove a new method of diagnosing Alzheimer’s Disease (AD) using microwave techniques.

Keladi candik(Alocasia longiloba Miq.) petiole extracts promote wound healing in a full thickness excision wound model in rats

Objective: To investigate the wound-healing effect of Alocasia longiloba(A. longiloba) petiole extract on wounds in rats.Methods: Twenty-two male Sprague-dawley rats were randomly assigned to receive 10% solcoseryl gel, phosphate buffer saline, 50% ethanol, 95% ethanol and hexane extracts of A. longiloba at 1.5%, 3% and 6% doses, respectively. A full thicknesses wound(6 mm) was created on the dorsal of the rat; and all rats were applied with the extract solutions, 10% solcoseryl gel and phosphate buffer saline once a day topically until day 12. The wound was photographed on day 1, 6 and 12, and the percentage of wound contraction was calculated. On day 12, rats were sacrificed and histological examination of granulation tissue was carried out using haematoxylin & eosin and Masson's Trichrome stain to determine the wound healing effect.Results: In this study, 6% of 50% and 95% ethanol extracts of A. longiloba showed 82.50% and 82.32% wound contraction, respectively, and were comparable with 10% solcoseryl gel(82.30%). Meanwhile, phosphate buffer saline treated group showed the lowest wound contraction(69.86%). Histological assessment of wound treated with 6% of 95% ethanol extract of A. longiloba showed distinct epidermal and dermal layer, higher proliferation of fibroblast and more angiogenesis with collagen compared to other wound treated groups.Conclusions: A. longiloba petiole extracts have a wound healing potential and 6% of 95% ethanol extract of A. longiloba is more effective. Further studies are required to understand the wound healing mechanism of action of the extract.

Morphometric study on Leydig cells in capsulotomized testis of rats

AIM: To further clarify the changes occurred in the testicular capsulotomized rats. METHODS: In testicular capsulotomized and sham-operated rats, the cross sectional area, the nucleus diameter and the number of Leydig cells were morphologically analyzed by the Vidas Image Processing System connected to a microscope. RESULTS: In the capsulotomized animals, the cross sectional area of Leydig cells was gradually increased from 30 days onwards. There was no obvious change in the nucleus diameter of Leydig cells. However, The Leydig cell number was significantly increased from day 30 onwards. CONCLUSION: In rats, testicular capsulotomy may induce hyperplasia/hypertrophy of Leydig cells in the testis.

Evaluation of the Haematinic Activities of Extracts of <i>Justicia secunda</i>Vahl Leaves in Red Blood Cells of Laboratory Rats

The use of plant parts (leaves, flowers, stems, barks, roots etc.) in traditional medicine is increasingly gaining ground in modern medicine, as plant sources have long been recognized as sources of secondary metabolites which can be used to treat a wide range of diseases. The effect of extracts of Justicia secunda leaves on red blood cells (RBC) count and haemoglobin (Hb) concentration was investigated in adult Sprague-Dawley rats to establish haematinic activity. Phenylhydrazine (PHZ)-induced anaemic rats were treated with water, methanol or ethyl acetate extracts at 200 mg/kg body weight. RBC counts and Hb concentration were analysed using a haematology analyser at 3-day intervals for 21 days. The extracts were compared with rats administered the haematinic tonic Feroglobin&reg;?and vehicle-treated (normal saline). Rats administered the water extract exhibited the most significant increase (P ) in the number of RBCs and Hb concentration compared with the vehicle-treated PHZ-induced anaemic rats. Rats administered the methanol extract followed with significant increase (P ) in RBC counts and Hb concentration (J. secunda leaves has excellent haematinic properties and this provides the pharmacological basis of its use in Ghanaian traditional medicine for the treatment of anaemia.

Selective control by posterior spinal nerve roots of micturition and erection in rats

The posterior rootlets in L6 and S1 spinal cord of adult male Sprague-Dawley rats underwent electrostimulation. The bladder pressure, urethral perfusion pressure and intracavernous pressure were recorded. When some posterior rootlets of L6 and Sl were electrostimulated, the intracavernous pressure peaked rapidly, but the bladder pressure and the urethral perfusion pressure curve did not show great change. When other rootlets were stimulated, the bladder pressure changed greatly, but the urethral perfusion pressure and the intracavernous pressure did not show great change. When different rootlets were stimulated, the urethral perfusion pressure changed maximally, but there were no great changes in bladder pressure or intracavernous pressure. Furthermore, stimulation of some rootlets produced simultaneous changes in two or three different pressure measures mentioned above. The results demonstrate that regulation by L6 and S1 posterior rootlets of the rat bladder detrusor, external urethral sphincter and penis cavernous body are significantly distinct. Different rootlets can be distinguished by electrostimulation.

Evans blue staining to detect deep blood vessels in peripheral retina for observing retinal pathology in early-stage diabetic rats

AIM: To observe and compare the statistical significance of superficial and deep vascular leakage in the pathological changes of the diabetic rats retina after the Evans blue(EB) perfusion, and utilize the modified whole-retina spreading method to make the slides while protecting the periphery of the retina. METHODS: The Sprague-Dawley(SD) rats were randomly divided into 6 groups. Each group named as the normal groups for 4, 8, and 12 wk and the diabetic groups for 4, 8, and 12 wk. The EB was injected into the cardiovascular system of the rats at the different time points. The retina of each group was obtained for observation.RESULTS: The superficial vascular leakage was found in all 6 groups. The size of leakage area of superficial retinal blood vessels was(0.54±0.23)%,(0.65±0.11)%,and(0.58±0.10)% in normal group. No notable leakage was found in the deep blood vessels [(0.03±0.04)%,(0.03±0.05)%, and(0.03±0.05)%]. The deep retinal vascular leakage was found in the peripheral retina of diabetic rats. The size of leakage area of superficial retinal blood vessels in diabetic group were(0.53±0.22)%,(0.69±0.16)%, and(0.52±0.11)%. The leakage areas of deep blood vessels were(0.54±0.50)%,(1.42±0.16)%, and(1.80±0.07)% at 4, 8, and 12 wk, respectively. There was a statistically difference of the leakage area between the 8 th week and the 4 th week of diabetes group(P=0.003). The statistically significant difference between the diabetes and the control groups was noted at 4 wk and 8 wk(P<0.001).CONCLUSION: The main retinal pathological changes of early-stage diabetic rats are the vascular leakage of the periphery of deep retina. Diabetic rats modeled after 8 wk have semi-quantitative statistical difference compared with the normal rats, thus early intervention treatment research can start at this time point.

Effects of Different Electromagnetic Fields on Circadian Rhythms of Some Haematochemical Parameters in Rats

Objective To investigate the effects of different electromagnetic fields on some haematochemical parameters of circadian rhythms in Sprague-Dawley rats. Methods The study was carried out in 18 male and 18 female rats in good health conditions exposed to 50 Hz magnetic sinusoid fields at the intensity of 1000 μT, 100 μT, and 0 μT （control group） respectively, and in 18 male and 18 female rats in good health conditions exposed to 1.8 GHz electromagnetic fields at the intensity of 50 V/m, 25 V/m and 0 V/m （control group）, respectively. Following haematochemical parameters for glucose, triglycerides, and total cholesterol were measured. Results Different effects of electromagnetic fields on circadian rhythms of both male and female rats were observed. Different changes occurred in some haematochemical parameters for glucose, triglycerides, and total cholesterol （P〈0.05）. Conclusion Exposure to different electromagnetic fields is responsible for the variations of some haematochemical parameters in rats.

Protective Effect of Fufang Yatongding on Periodontitis Model Rats

[Objectives]The paper was to investigate the protective effect of Fufang Yatongding on experimental periodontitis in rats.[Methods]Experimental periodontitis rats were randomly divided into blank group(5 rats),model group,control group and experimental group,with 8 rats in each group.The rats in the blank group were fed with normal diet,and those in the model group,control group and experimental group were administered intragastrically with normal saline,minocycline hydrochloride solution and Fufang Yatongding solution,respectively.After 4 weeks,alveolar bone resorption was measured.Serum matrix metalloproteinases(MMPs)and inflammatory factors were detected by ELISA,and the changes in gingival tissue were observed by HE staining.[Results]Compared with the control group,the distance from enamel cementum to alveolar crest in the experimental group was decreased(P<0.05).Compared with the control group,the levels of serum MMPs and inflammatory factors in the experimental group were decreased(P<0.05).The results of HE staining showed that the cells in the gingival tissue of rats in the blank group were normal in morphology and intact in structure,and the cells in the gingival tissue of rats in the model group were damaged and out of order,while the cells in the control group were slightly intact and arranged orderly,and the pathological damage of rats in the experimental group was less than that in the control group.[Conclusions]Fufang Yatongding has protective effect on experimental periodontitis in rats by inhibiting the release of MMPs and inflammatory factors.

Reference values for selected hematological, biochemical and physiological parameters of Sprague‐Dawley rats at the Animal House, Faculty of Medicine, University of Colombo,Sri Lanka

Background: Lack of available reference values in a research setting under local conditions can be a drawback for beginners, as the accuracy of data from control samples cannot be checked at the beginning of a research project. This affects comparisons with data from test samples. To avoid these complications in their research projects,beginners tend to have a greater number of animals in the control group compared to test groups in order to have control group measurements within 2 SDs of the mean.Methods: As non-availability of reference values was a long-felt need, the described project was conducted in order to establish a reference database for selected haematological, biochemical and physiological parameters using apparently healthy Sprague-Dawley rats bred in the Animal House of Faculty of Medicine, University of Colombo(UCFM).Results: Differences in mean values of packed cell volume(PCV), mean corpuscular volume(MCV) and mean corpuscular hemoglobin concentration(MCHC), serum creatinine and blood glucose levels between the two genders were statistically significant. Lipid profile measurements did not differ significantly between genders, but mean and median values of triglycerides(TG) between male and female rats showed a difference of more than 10 mg/dL. The liver enzymes alkaline phosphatase(AP)and aspartate aminotransferase(AST) were also statistically significantly different between sexes. Despite wide variation in mean alanine aminotransferase(ALT)between sexes, the difference was not statistically significant.Conclusion: The findings of this project should support to a certain extent the"Reduction" aspect of the 3 Rs concept of Russell and Burch by reducing the number of Sprague-Dawley rats used in future research projects at UCFM.

2017~2021年陕西省实验动物使用单位SPF级大、小鼠质量监测结果分析与评估

目的分析2017~2021年陕西省部分实验动物使用单位无特定病原体(specific pathogen free,SPF)级大、小鼠微生物和寄生虫质量检测结果,了解各单位大、小鼠病原微生物学质量状况,为实验动物质量管理与监测提供参考依据。方法按照现行国家标准GB 14922.2-2011、GB/T 14926-2001和GB/T 14926.21-2008,由陕西省实验动物质量监督检测中心对大、小鼠进行病原微生物和寄生虫抽样检测并分析质量状况。结果2017年~2021年累计抽检109家单位的小鼠2549只,45家单位的大鼠503只。检测结果显示,小鼠体外寄生虫(螨虫)检出率由5.26%降为0.15%,肠道鞭毛虫由10.53%降为0.45%,肠道蠕虫由0.40%升至2.39%,沙门菌由2.78%降至无检出,泰泽病原体抗体阳性率由1.38%降至无检出;大鼠体外寄生虫(螨虫)检出率由7.07%降至无检出;肠道鞭毛虫由11.50%降为0.83%,蠕虫由3.79%升至7.50%,金黄色葡萄球菌由1.77%降至无检出。小鼠病毒血清抗体阳性率,2017年检出小鼠肝炎病毒(4.71%)、仙台病毒(1.39%)和小鼠细小病毒(2.22%),2021年出小鼠肝炎病毒(0.30%)和仙台病毒(0.15%),小鼠肺炎病毒阳性率则由1.11%升至2.39%,小鼠呼肠孤病毒Ⅲ型由0.17%升至0.45%。大鼠仙台病毒阳性率由7.07%降为0.83%,大鼠细小病毒和大鼠冠状病毒仅2017年和2018年在个别单位有检出,大鼠肺炎病毒则由0.88%增长为10.00%。结论近5年的检测结果表明,陕西省实验动物使用单位的大、小鼠病原微生物质量逐年提升,但仍存在一定问题,应持续采取严格的生物安全防控措施,加强动物实验过程,确保各单位在实验周期内动物质量合格。

普通级、SPF级SD大鼠、Wistar大鼠血常规的测定与比较

目的 测定普通级、SPF级SD大鼠、Wistar大鼠血常规指标并进行比较。方法 Coulter -JT全自动血常规检测仪自动检测。结果 普通级、SPF级SD大鼠白细胞计数、红细胞计数、血红蛋白、血小板计数、血小板平均分布宽度、红细胞平均分布宽度相差非常显著 (P <0 0 1) ;中性粒细胞、单核细胞相差显著 (P <0 0 5 )。普通级、SPF级Wistar大鼠白细胞计数、中性粒细胞、单核细胞、红细胞计数、红细胞平均体积、平均红细胞血色素量相差非常显著 (P <0 0 1) ;血红蛋白、血小板计数、血小板平均分布宽度相差显著 (P <0 0 5 ) ,其他指标相差不显著。结论 不同微生物学环境对SD。

10种常见SPF级实验大、小鼠血液学及生化指标正常参考值的探讨

目的建立10种常见SPF级实验大、小鼠血液及生化正常参考值。方法采用半自动生化测定仪及血球计数仪对不同周龄、不同性别的常见10种SPF大鼠的血液学指标及生化指标值进行测定。结果取得4周龄和8周龄不同周龄、不同性别大、小鼠血液学及生化值平均值及正常参考范围;多数生化指标受年龄及性别的影响,除了不同品系、年龄和性别的大、小鼠ALP呈现规律性变化,其他指标也与相关报道有差异。结论在基础生物学研究中,要充分考虑到性别和年龄对实验动物血液学及血清生化指标的影响。

不同周龄和性别的SPF级SD大鼠血液生理生化指标的测定与比较分析

目的研究周龄和性别对SPF级SD大鼠血液生理生化指标的影响,建立不同周龄和性别SD大鼠血液生理生化指标正常值背景资料。方法离乳3周龄SPF级SD大鼠80只,雌雄各半,随机分为4、12、24、48周龄4个实验组,采用全自动生化分析仪及血液细胞分析仪对大鼠的血液生理生化指标进行测定,统计并分析同性别周龄间和同周龄性别间指标差异。结果 4周龄与12、24、48周龄大鼠的生理指标如白细胞(WBC)、红细胞(RBC)、血红蛋白(HGB)、血细胞压积(HCT)、红细胞平均体积(MCV)、红细胞平均血红蛋白含量(MCH)、红细胞平均血红蛋白浓度(MCHC)、血小板(PLT)、血小板压积(PCT)、嗜碱性细胞数(BA#)、嗜碱性细胞百分比(BA%)及生化指标如谷草转氨酶(AST)、总胆固醇(CHOL)、总蛋白(TP)、血糖(GLU)、肌酐(CRE)、丙氨酸转氨酶(ALT)、碱性磷酸酶(ALP)、尿素氮(BUN)、甘油三酯(TG)等比较,差异均有统计学意义(P<0.01或0.05)。4周龄大鼠血液BA%和24周龄大鼠血液BA#均为雌雄间差异有统计学意义(P<0.05);12和24周龄大鼠血液WBC、RBC雌雄间差异有统计学意义(P<0.01或0.05);48周龄大鼠血液MCH、PCT雌雄间差异有统计学意义(P<0.01)。4周龄大鼠血液CRE雌雄间差异有统计学意义(P<0.01);12周龄大鼠血液AST、CHOL、BUN和48周龄大鼠血液GLU均为雌雄间差异有统计学意义(P<0.05);4、12和24周龄大鼠血液ALP雌雄间差异有统计学意义(P<0.01或0.05)。结论同性别不同周龄的SPF级SD大鼠血液生理生化指标差异有统计学意义,同周龄不同性别的SD大鼠之间也存在一定差异。

10种常用SPF级实验大、小鼠体重及主要脏器的测定

目的测定10种常用SPF级大、小鼠体重、脏器及肠道等正常参考值。方法解剖10种品系实验动物,称量各组织脏器的相对重量,用尺测量肠道长度,共对9种脏器指标进行了测定。结果不同品系动物的各种脏器指标有明显差别,即使是同种品系,不同性别间也存在差异。

不同日龄SPF级Wistar大鼠血液生化参考值的建立

目的建立不同日龄SPF级Wistar大鼠血液生化参考值。方法采用全自动生化测定仪对20、30、40、50日龄SPF级Wistar大鼠的血液27项生化指标进行测定,并进行统计分析和差异显著性检验。结果建立了203、0、40、50日龄SPF级Wistar大鼠27项生化参考值,20、30日龄SPF级Wistar大鼠雌雄之间部分指标差异显著,40、50日龄SPF级Wistar大鼠雌雄之间差异显著占一半以上,不同日龄之间各项指标存在一定的差异,并且变化规律不同。SPF级Wistar大鼠不同日龄的ALT、ALB、CREA、AG、TP、GLB、ALP、TG、MG随日龄升高而升高;PO4、AST/ALT、BUN、URIC、BUN/CREA、CK、LD、CHOL、CL、OSM随日龄升高而降低,AST、CA差异不显著。结论SPF级Wistar40日龄以上的大鼠血液生化指标易受性别、年龄等的影响,SPF级Wistar大鼠血液生化指标的一致性较好。