230,559 research outputs found

    Faecal corticosterone metabolite assessment in socially housed male and female wistar rats

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    Knowledge of animals’ hormonal status is important for conservation studies in wild or semi-free-ranging conditions as well as for behavioural and clinical experiments conducted in laboratory research, mostly performed on rats and mice. Faecal sampling is a useful non-invasive method to obtain steroid hormone assessments. Nevertheless, in laboratory studies, unlike other contexts, faecal sampling is less utilised. One of the issues raised is the necessity to collect samples belonging to different animals, separately. Usually, researchers using faecal sampling solve this problem through the isolation of animals or taking the cage rather than single animal as unit of study. These solutions though, could lead to unreliable measurements, and cannot be applied in many studies. Our aim was to show the biological reliability of individual faecal corticosterone metabolite (FCM) assessments in socially housed male and female Wistar rats. We analytically validated the enzyme immunoassay kit used for FCM assessments. Then, we exposed the animals to two different stress stimuli that are known to activate the hypothalamus–pituitary–adrenal axis and the following release of corticosterone to biologically validate the EIA kit: environmental enrichment and predator odour. Individual faecal sampling from social animals was collected through short-time handling. The results demonstrated that both the stimuli increased FCM levels in male and female rats showing the reliability of EIA kit assessment and the applicability of our sampling method. We also found a diurnal rhythm in FCM levels. These results could help to increase the use of faecal hormone metabolite determinations in studies conducted on rats

    Overview of laboratory animal lifestyle, care, and management: a case study of albino rats

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    The review was design to look at an overview of laboratory animal’s lifestyle, care and management using albino rats as case study. The use of laboratory animals (albino rats) in scientific research can be dated as far back as 16th century. Thus, using laboratory animals in scientific research as model to human with expectation that such use will provide either significant new knowledge or lead to improvement in human and animal well-being should be considered as a privilege granted by society to research communities. The environment is central to laboratory animal care, management and welfare and must be considered throughout the breeding holding and experimental phase under standard laboratory conditions and a well-controlled environment to keep them healthy. The factors affecting health and welfare of the animals include noise, temperature, humidity, ventilation and daylight/darkness. The nutritional requirement of some laboratory animals are fairly documented, the animals however, should have access to clean reliable water at libitum and wholesome, clean nutritious palatable diet on regular basis to ensure the appropriate intake of protein, fat, carbohydrate vitamins, salt, minerals and fibre. Euthanizing of laboratory animals should be carried out in three main circumstances which include culling of unwanted animals, relief of suffering in individual animal and the techniques chosen should strive to achieve quick, quiet and painless death and thus, should not induce fear, apprehension or panic in the animal. The other animals left should be well protected from the sight, sound, and smell of the procedure and therefore, not to be carried out in public areas.Keywords: Laboratory, Animal, Rats, Management and Welfar

    A Simple, Inexpensive, and Effective Light- Carrying Laryngoscopic Blade for Orotracheal Intubation of Rats

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    The research paradigm of using large laboratory animals, in which oroendotracheal intubations are relatively easy, is shifting toward the use of small animals, such as rodents, in which oropharyngeal access is limited, the arytenoid cartilage cycles are faster, and the glottis is much smaller. The considerable growth recently seen in preclinical imaging studies is accompanied by an increased number of rats and mice requiring in vivo intubation for airway management. Tracheal access is important for ventilation, administration of inhaled anesthetics, instillation of drugs or imaging agents, and maintenance of airway patency to reduce mortality during and after operations. I fashioned a light-carrying laryngoscopic blade (laryngoscope) from readily available acrylic-polymethyl methacrylate tubing and used it to perform rapid, effective tracheal intubation in rats. The laryngoscope design and intubation techniques are presented

    Effects of muscle atrophy on motor control

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    As a biological tissue, muscle adapts to the demands of usage. One traditional way of assessing the extent of this adaptation has been to examine the effects of an altered-activity protocol on the physiological properties of muscles. However, in order to accurately interpret the changes associated with an activity pattern, it is necessary to employ an appropriate control model. A substantial literature exists which reports altered-use effects by comparing experimental observations with those from animals raised in small laboratory cages. Some evidence suggests that small-cage-reared animals actually represent a model of reduced use. For example, laboratory animals subjected to limited physical activity have shown resistance to insulin-induced glucose uptake which can be altered by exercise training. This project concerned itself with the basic mechanisms underlying muscle atrophy. Specifically, the project addressed the issue of the appropriateness of rats raised in conventional-sized cages as experimental models to examine this phenomenon. The project hypothesis was that rats raised in small cages are inappropriate models for the study of muscle atrophy. The experimental protocol involved: 1) raising two populations of rats, one group in conventional (small)-sized cages and the other group in a much larger (133x) cage, from weanling age (21 days) through to young adulthood (125 days); 2) comparison of size- and force-related characteristics of selected test muscles in an acute terminal paradigm

    Increased Biodiversity in the Environment Improves the Humoral Response of Rats

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    Previous studies have compared the immune systems of wild and of laboratory rodents in an effort to determine how laboratory rodents differ from their naturally occurring relatives. This comparison serves as an indicator of what sorts of changes might exist between modern humans living in Western culture compared to our hunter-gatherer ancestors. However, immunological experiments on wild-caught animals are difficult and potentially confounded by increased levels of stress in the captive animals. In this study, the humoral immune responses of laboratory rats in a traditional laboratory environment and in an environment with enriched biodiversity were examined following immunization with a panel of antigens. Biodiversity enrichment included colonization of the laboratory animals with helminths and co-housing the laboratory animals with wild-caught rats. Increased biodiversity did not apparently affect the IgE response to peanut antigens following immunization with those antigens. However, animals housed in the enriched biodiversity setting demonstrated an increased mean humoral response to T-independent and T-dependent antigens and increased levels of “natural” antibodies directed at a xenogeneic protein and at an autologous tissue extract that were not used as immunogens

    Experimental Combat-Stress Model in Rats: Histological Examination of Effects of Amelogenesis-A Possible Measure of Diminished Vagal Tone Episodes

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    Developmental defects of enamel-stress histomarker rings (accentuated striae) may be a potential measure of diminished vagal tone in research on extreme stress such as exposure to combat. To develop an animal model of this measure, we examined the enamel of rat incisors which erupt continuously. We examined incisors from 15 stressed-colony rats and 7 control-rats for these histomarkers using the Visible Burrow System (VBS). VBS was developed to study combat stress in rats. No stress rings were found in any of the rat incisors examined. In contrast to humans, rats have likely evolved to prioritize incisor strength during combat stress. Studies of amelogenesis during combat stress in other rodents with continuously growing incisors are warranted. Laboratory animals such as rabbits or marmosets may be especially suitable, since they less frequently use their incisors for self defense

    Deteksi Endoparasit Cacing pada Hepar Tikus Laboratorium (Rattus norvegicus) dari Sentra Peternak di Kabupaten Banyumas dan Kabupaten Purbalingga

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    The presence of laboratory rats that are maintained and bred for laboratory purposes or laboratory observations is very necessary. The presence of endoparasite in laboratory rats will have an impact on the result of the research or laboratory observations. This study aims to detect helminth endoparasites in the liver of laboratory rats (Rattus norvegicus) from animal breeders in Banyumas and Purbalingga Districts. This research was an observational study with a cross-sectional design. A total of 52 laboratory rats were used in the study. Rats are killed with chloroform, liver surgery then identify the presence of worm larvae. Out of the 52 rats obtained, 7 (29.17%) from 24 laboratory rats in Banyumas District and 5 (17.86%) from 28 laboratory rats in Purbalingga District were infected with Taenia taeniaeformis. It is necessary to control helminth infections in laboratory rats, such as laboratory animal quarantine, health monitoring, and antihelmintic treatment. It is important to handle carefully during travel to assure the results of research or laboratory observations using the animals

    Standardisation of Environmental Enrichment for Laboratory Mice and Rats: Utilisation, Practicality and Variation in Experimental Results

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    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.

    Numbers of Publications Related to Laboratory Animals

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    Laboratory animals are widely utilized in biomedical research, so a search of scientific publications can  give us useful information on the use of animals. We retrieved the PubMed biomedicine database and  searched for publications related to laboratory animals from 1966 to 2005. We found that rats and mice  constitute the vast majority of species used in biomedical research; C57BL and BABL/c inbred mice, and  Sprague Dawley and Wistar outbred rats are the most common strains. Recently, the numbers of publications  relating to traditionally used animals such as rats, guinea pigs, dogs, cats, and sheep decreased slightly,  whereas the numbers relating to mice, fish, Drosophila and Caenorhabditis elegans increased from 1995  to 2005, with annual mean growth rates of 4.5%, 8.22%, 1.95%, and 10.3%, respectively. Publications  involving transgenic mice increased dramatically from the mid-1980s. This survey provides significant  clues for predicting the future direction of biomedical research.

    Methodology for estimation of total body composition in laboratory mammals

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    A standardized dissection and chemical analysis procedure was developed for individual animals of several species in the size range mouse to monkey (15 g to 15 kg). The standardized procedure permits rigorous comparisons to be made both interspecifically and intraspecifically of organ weights and gross chemical composition in mammalian species series, and was applied successfully to laboratory mice, hamsters, rats, guinea pigs, and rabbits, as well as to macaque monkeys. The procedure is described in detail
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