2010 - Volume 37 - Issue 2

61-66
Beta-Cyfluthrin Induced Histochemical Alterations in the Liver of the Albino Rat
by Brijender Bhushan, Nishi Saxena & Prabhu Narain Saxena

Pesticide poisoning and related diseases have gained considerable attention in the recent past. Beta-cyfluthrin is a type II pyrethroid pesticide and is widely used against crop and house hold pests. The present study has been designed to assess histochemical alterations following beta-cyfluthrin intoxication in the liver of the female albino rat (Rattus norvegicus). Beta-cyfluthrin was orally administrated, 35.48 mg/kg b.wt. for acute (1 day) and 5.06, 2.53 and 1.68 mg/kg b.wt. for sub-acute (7, 14 and 21 days) treatments respectively. Beta-cyfluthrin caused marked hepatotoxicity in the form of altered hepatosomatic index viz. liver weight, body weight and liver weight-body weight ratio and histochemical localization of DNA and proteins in the liver of albino rat. On the basis of histochemical study, it could be revealed that beta-cyfluthrin causes a reduction in hepatic proteins and an enhancement in the hepatic DNA. The centrilobular zone was the zone of maximum alteration followed by the midzone and periportal zone of the hepatic lobule. Decreased protein content is a consequence of lysis of structural proteins and the need to support increased cell proliferation under stress of beta-cyfluthrin, whereas increased DNA is a consequence of increased mitogenic activity resulting in excessive cell proliferation. It is proposed that xenobiotic metabolising enzymes, which are most concentrated in the centrilobular zone, cause the formation of metabolites of beta-cyfluthrin, which are toxic to the liver. Lower oxygen levels in the centrilobular zone, compared to other parts of the liver lobule, may have also contributed to the observed histochemical changes being greatest in the centrilobular zone.

69-72
A Special, Modified, Double-Lumen Tube for One-Lung Ventilation in Pigs
by Konrad Schwarzkopf, Lars Hueter, Niels-Peter Preussler, Florian Setzer, Torsten Schreiber & Waheedullah Karzai

Animal studies in pigs often depend in thoracic anaesthesia on effective lung separation. In this report we describe the use of a modified double-lumen endotracheal tube for one-lung or differential lung ventilation in pigs resulting in excellent lung separation and unimpaired hypoxic pulmonary vasoconstriction.

75-82
Anti-Apoptosis Effect of Astragaloside Iv on Alzheimer's Disease Rat Model via Enhancing the Expression of Bcl-2 And Bcl-Xl
by You Yin, Yan Liu, Liuqing Huang, Shuqi Huang, JianHua Zhuang, Xiaoyan Chen, Lin Zhang,
Huijuan Wu, Fuyuan Shao & Zhongxin Zhao

The aim is to explore the protective effect of Astragaloside IV on Alzheimer’s disease (AD) in rats induced by amyloid-ß peptide (Aß_1-42) and its potential therapeutic mechanism. Methods: 50 Male Sprague Dawley rats were divided into five groups (10 rats for each): control group, model group, treatment groups 1~3. 10μg Aß_1-42 was injected bilaterally into the dorsal dentate gyrus of the hippocampus of rats in the model and treatment groups to prepare the AD models. 24h after modeling, Astragaloside IV administration, with different drug dosages of 20mg/(kg•day), 40mg/(kg•day) and 60mg/(kg•day), was performed by gastric perfusion for rats in the treatment group 1~3. Later on, the cognitive ability of rats was examined by a series of behavioral tests, and the expression of Bcl-2 and Bcl-xl in the hippocampus of rats was detected by the fluorescein based Quantitative RT-PCR. Results: The spontaneous alternation test in a Y maze and Morris water maze task have demonstrated that the repeated daily administration of Astragaloside IV at the doses of 20mg/kg bw/day) (p<0.05), 40mg/kg bw/day) (p<0.01), and 60mg/kg bw/day) (p<0.01) significantly ameliorated the impairment of performance caused by Aß_1–42. Furthermore, Astragaloside IV also enhanced the expression of Bcl-2 and Bcl-xl in hippocampal neurons of rats in a dosage-dependent manner. Conclusion: These findings suggest that Astragaloside IV could alleviate cognitive impairment and enhance the expression of Bcl-2 and Bcl-xl in hippocampus of rat models with AD.

85-90
Proliferative Response of Hamster CD4+ T Cells after Different Mitogenic Stimulation
by Salvador Fonseca-Coronado, Eugenio Del Valle-Espinosa, Sigifredo Pedraza-Sánchez & Ana Flisser

The measurement of effector cells involved in immune responses is an important parameter in various fields of lymphocyte research using the Syrian Golden hamster as the experimental model. The aim of the present study was to identify the percentage of peripheral hamster CD4+ cells that undergo proliferation and the number of cell divisions induced by four different mitogenic compounds: phorbol-myristate acetate plus ionomycin (PMA/ionomycin), concanavalin A (Con A), phytohaemagglutinin (PHA) and the superantigen Staphylococcal enterotoxin B (SEB). The proliferative response was investigated by the use of the cross-reactive mouse anti-CD4 antibody (clone H129.9) and analyzed by flow cytometry using the dye carboxyfluorescein diacetate succinimydil ester (CFSE). PMA/ionomycin induced the highest proliferative response of CD4+ cells. Interestingly, the down-regulation in the CD4 expression described after PMA/ionomycin activation both in human and in mouse lymphocytes was not seen in hamster cells. Stimulation with SEB and with Con A also induced up to 6 to 7 proliferation cycles in cells, whereas PHA induced the lowest proliferation. These results provide useful tools for the study of CD4+ cells in the hamster model.

93-99
Differential Leukocyte Counts of SJL/J Mice with Dysferlinopathy Treated with Resveratrol and Coenzyme Q₁₀
by Wendy J van der Spuy, Marnie Potgieter, Etheresia Pretorius & Warren A Vieira

Dysferlinopathies include Limb-Girdle Muscular Dystrophy type 2B and Miyoshi Myopathy, which exhibit an autosomal recessive inheritance pattern of the dysferlin gene and characteristic inflammatory infiltrate in muscle. A study of prospective treatment options was conducted on SJL/J mice, a natural model for dysferlinopathy. The animals are immunocompetent but have elevated levels of circulating T-cells. A baseline termination of SJL/J mice was made at 14 weeks, and differential leukocyte counts determined for these animals through microscopy. After administration of resveratrol and Coenzyme Q₁₀ exclusively and in combination to the four treatment groups for approximately three months, the remaining six groups (negative and positive controls as well as four treatment groups) were terminated and differential leukocyte counts once again determined. Eosinophil counts were significantly higher in the baseline termination group than all other experimental groups assessed except for the negative control SWR/J mice, possessing normal muscle and used in research as a general purpose strain. Eosinophil granules are suggested to reduce inflammation caused by other leukocytes. At onset of dysferlinopathy between four and six weeks of age, the increase in eosinophil counts could very likely be a compensation mechanism to decrease initial inflammation in the muscular tissues of the dysferlinopathic mice. Neutrophil counts of the baseline termination group were significantly higher only when compared to the resveratrol/Coenzyme Q₁₀ combination group. Neutrophils are linked to early inflammatory responses and often sensitised in self-antigen recognition characteristic of autoimmune disease, a known complication in the SJL strain. Thus the higher neutrophil count in the six week old mice is probably related to inflammation at disease onset, but may also be indicative of autoimmunity; whereas the eosinophil counts may possibly play a more definitive role in the pathogenesis of dysferlinopathy. Further morphological studies will serve to clarify the roles of these leukocytes in dysferlinopathy.

101-114
Standardisation of Environmental Enrichment for Laboratory Mice and Rats: Utilisation, Practicality and Variation in Experimental Results
by V. Baumans, P.L.P. Van Loo & T. M. Pham

Rats and mice are the most commonly used species as laboratory animal models of diseases in biomedical research. Environmental factors such as cage size, number of cage mates and cage structure such as environmental enrichment can affect the physiology and behavioural development of laboratory animals and their well-being throughout their lives. Therefore compromising the animals’ well-being due to inadequate environmental conditions would diminish the value of the research models. In order to improve laboratory animals’ well-being and promote the quality of animal based biomedical research, it is fundamentally important that the environment of the animals meets the animals’ species typical behavioural needs. Standardisation of environmental enrichment for laboratory rats and mice therefore should provide possibilities for the animals to engage in at least the essential behavioural needs such as social contact, nest building, exploring and foraging. There is a wide variety of environmental enrichment items commercially available for laboratory mice and rats. However, how these items are used by the animals, their practicality in the laboratory and whether these enrichments might lead to increased variation in experimental results have not been widely assessed. In this study, we implemented two standardised enrichment items (shelters, nesting materials) for rats and mice at different animal units. We instructed the animal care staff in monitoring the use of enrichment items by the animals by means of a daily score sheet system. The animal staff ’s viewpoint on practicality of the standardised enrichment program was assessed with a monthly score sheet survey. Also we assessed whether the enriched environment affected breeding results and contributed to an increase in variation of experimental data from several participating current studies. Our results show that the animals readily used the provided enrichment items. A slight increase in workload for the animal staff was reported. However, the overall judgement was mainly reported as good. Breeding results and variation in experimental data did not reveal differences as compared to data from previous housing and/or non enriched housing conditions. Overall, the results indicate that standard environmental enrichment that is species appropriate may enhance the animal’s well-being without undesirable side effects on the experimental outcome and daily working routine of the animal care staff.

117-127
A New Fiducial Marker for Gated Radiotherapy in the Lung – A Feasibility Study of Bronchoscopy Based Insertion and Removal in Göttingen Mini-Pig
by Jesper Carl, Henrik Kirstein Jensen, Jane Nielsen, Martin Skovmos Nielsen, Markus Schmid & Siegfried Loeschke

To develop a new prototype fiducial marker (LS-1) that may be used for gated radiotherapy in the lung. One LS-1 marker was inserted in the lung of each animal under sedation. Animals were kept under observation for four weeks after insertion. After the observation period the marker was removed. Animals were CT scanned after insertion and before removal of the LS-1 marker. After the last CT scan animals were euthanized and lungs excised for pathology. The LS-1 marker was successfully inserted in all fourteen animals. Thirteen of fourteen LS-1 marker’s were in situ after four weeks. Two cases of pneumothorax were seen in connection with insertion. The LS-1 marker could only be successfully removed from eleven of thirteen animals. Damage to the lung was mainly local close to the LS-1 marker insertion site. The LS-1 marker has the potential to be a fiducial marker suitable for gated external beam radiotherapy in the lung. The method still needs some refinement prior to application in humans.