Determination and comparison of the bone mineral density of different skeletal regions of female Wistar rats at different ages / 中国比较医学杂志

Objective To provide reference values for bone mineral density(BMD)in different skeletal regions of female Wistar rats at different ages. Methods Thirty SPF female Wistar rats were selected. The BMD of different skeletal regions(skull,upper limbs,thighs,trunk,ribs,pelvis,spine and the whole body)was measured by dual energy X-ray absorptiometry(DXA)at 6,10,12,24 and 30 months of age. The bone mineral densities between different age groups and that of different skeletal regions in the same age groups were compared. Results The BMD of the skull,upper limbs,thighs,trunk,ribs,pelvis, spine and the whole body was increased rapidly with age, and reached a peak at 10 months of age. The BMD of the skull,upper limbs,thighs,trunk,ribs were significantly higher than the whole body BMD in the same month-age group(P< 0.05 or P< 0.01). However,there was no significant difference between the pelvic, spine and the whole body BMD(P> 0.05). There was a significant positive correlation among the three correlations(P<0.01). Conclusions Some background data are provided for the bone biology studies of female Wistar rats, and provide useful supplementary reference for the studies of bone metabolism in rats and their application in biomedicine.

Biopsy of liver and kidney tissues in rhesus monkeys under B-mode ultrasound guidance / 中国比较医学杂志

Objective To establish a safe and effective method of rhesus monkey biopsy to take liver and kidney samples under B-mode ultrasound guidance. Methods A total of 4 adult monkeys(weight:8-12 kg; sex: male; age:11 -12 years old)were anaesthetized with 5 -10 mg/kg of ketamine hydrochloride for each through intramuscular injection. After successful anesthesia, abdominal shaving and iodophor disinfection, they were monitored from intercostal area of right upper quadrant or lateral waist subcostal abdomen portions to find liver or kidney organ by MyLab 30CV B-mode ultrasonography with 3.5 Hz transducer which was fixed with a guiding frame. Large vessels such as the portal vein and inferior vena cava were carefully avoided. The range of the biopsy gun was set to 15 mm. When the puncture target and the puncture needle were positioned in the guide line, the puncture target was perpendicular to the puncture needle, and then the trigger button of the puncture needle was pressed to obtain the liver or kidney tissue samples respectively. After puncture,the needle was pulled out quickly. The obtained liver and kidney tissues were used to extract RNA. Results About 13 mg of liver or kidney tissue was obtained by each puncture with volume convertion. This method was fast,reliable and safe,and the total RNA had high purity and integrity. There was no postoperative bleeding and infection. Conclusions This is a very important method for obtaining liver and kidney tissue samples of rhesus monkeys with the guidance of ultrasound. With this method, the research cost can be reduced, the life quality and animal welfare of laboratory non-human primates can be improved,and the accuracy of experimental result can be ensured.

Exploration of establishing a tree shrew model of chronic gastrointestinal mucosal injury / 中国比较医学杂志

Objective To explore the feasibility of establishing a tree shrew model of chronic gastrointestinal mucosal injury. Methods A total of 12 adult male tree shrews were randomly divided into 3 groups. The experimental groups 1 and 2 were administered with intraperitoneal injection of 2 mg/(kg·d)and 1 mg/(kg·d)of 1-methyl-4-phenyl-1,2, 3,6-tetrahydropyridine(MPTP)once every day for 56 days, respectively. The control group was given the same volume of sterile saline at the corresponding time points. Changes in the body weight of the tree shrews were observed. The contents of dopamine in the cerebrospinal fluid were detected. Gastrointestinal morphology was observed by stereoscope and histopathological changes of the gastrointestinal mucosa were examined by HE staining. Results The body weight and the contents of dopamine in the cerebrospinal fluid of the tree shrews in the model group were significantly decreased(P< 0.05 for both). Pathological changes to some extent of the gastric antrum, the gastric body and the duodenum were observed, without obvious differences between the 2 mg/kg group and the 1 mg/kg group. No obvious changes were found in the control group. Conclusions Long-term intraperitoneal injection with a low dose of MPTP is a feasible method for the establishment of a tree shrew model of chronic gastrointestinal mucosal injury. The optimal dose is 2 mg/(kg·d)every day for 56 days.

Comparison between the quantitative and semi-quantitative fluorescence RT-PCR assays for the detection of XDH/XO mRNA expression in different organ tissues of rhesus monkey / 中国比较医学杂志

Objective To analyze the differences between the semi-quantitative RT-PCR and real time quantitative fluorescence RT-PCR assays for detecting XDH/XO mRNA expression in various organ tissues of rhesus monkey, and provide useful reference in methodology of experimental studies.Total RNA was extracted from the myocardium, kidney, testis, skin, and liver tissues, respectively, for detecting XDH/XO mRNA expression in rhesus monkey by semi-quantitative RT-PCR and real time quantitative fluorescence RT-PCR assays.The sensitivity and specificity of the two assays were compared with each other using the same primer sequences and reference genes.Results The expression of XDH/XO mRNA in different organ tissues were detected by both the two PCR assays.The sensitivity of quantitative fluorescence real-time RT-PCR for the XDH/XO mRNA expression in the liver tissue was 39 times higher than that by semi-quantitative RT-PCR.Conclusions Both the quantitative and semi-quantitative fluorescence RT-PCR assays can be used to detect the expression of XDH/XO mRNA in different organ tissues of rhesus monkey.The sensitivity of quantitative fluorescence real-time PCR assay is more sensitive than that of the semi-quantitative RT-PCR assay.

A murine model of LPS/D-gal-induced acute hepatitis and alterations in mTOR signaling / 中国实验动物学报

Objective To explore the changes of mTOR signaling in LPS/D-gal-induced acute hepatitis in mice . Methods Twenty-six healthy adult female ICR mice were divided into two groups:the control group and experimental group, 13 mice in each group .LPS/D-gal was used to induce acute hepatitis in the mice .The survival of mice was moni-tored within 24 hours after LPS/D-gal challenge .At 6 hours after challenge , samples of serum and liver tissue were collect-ed for further analysis.Results Injection of LPS/D-gal resulted in acute death of the mice within 24 hours.At 6 hours post LPS/D-gal injection , the blood levels of ALT and AST were significantly increased .The mRNA expression of inflammatory cytokines Tnfa and Il6 was up-regulated in LPS/D-gal-induced hapatitis , in which DNA fragmentation and activation of caspase-3 were subsequently observed .Immunoblot analysis showed that both mTOR pathway and NF-κB pathway were ac-tivated.Unexpectedly , inhibition of mTOR signaling could neither decrease the apoptosis in the liver nor increase the sur -vival of mice .Conclusions The results of the present study indicate that mTOR signaling may play pleiotropic roles in the pathogenesis of LPS/D-gal-induced hepatitis .