Animals In Experiments Research Articles

Influence of coagulated egg melange on the physical endurance of growing male Wistar rats: physiological and biochemical assessment

Melange, is one of the most commonly used products of egg processing, however, its use for the production of functional foods is limited by its liquid consistency. The range of functional foods, including those that increase physical endurance and working ability, can be expanded by using the coagulated form of the melange. Thus, the preclinical testing of the nutritional value of coagulated melange and the effect of its consumption on the physical endurance of laboratory animals is relevant. The aim of this research was the experimental comparative physiological and biochemical in vivo evaluation of the effects of coagulated melange consumption by Wistar male rats on their growth indices and physical endurance. Material and methods. Samples of the lyophilized egg melange (EM) and coagulated egg melange (CEM) were used as objects of the research The experiment was conducted with the use of 45 growing male Wistar rats with initial body weight 80±5 g. According to the preliminary training results, 27 animals were selected for further experiment. The motor function was evaluated by means of grip test. The rats were randomized into 2 experimental groups according to their weight and grip strength. Animals were treated for 32 days with isocaloric and isonitrogenic semi-synthetic diets with EM and CEM as protein component (25% of the dry weight), consequently. The grip test was conducted once per week, two days a week animals were trained on the treadmill for 10 min. On the 31st day of the experiment, animals were exposed to exhaustive training till total exhaustion. On the 32nd day of experiment animals were decapitated under light ether anesthesia. The concentration of glucose, triglycerides, cholesterol (CHL), high-density lipoproteins (HDL) and low-density lipoproteins (LDL) was determined in the blood serum. Results and discussion. The greater consumption of food (20±1 g/rat/day) containing CEM by animals corresponded to a greater increase (204±9%) of their body weight over the entire experiment period compared with animals that received EM (13±1 g/rat/day; 160±9%, respectively, p≤0.05). An increase in the intake of food containing CEM had a pronounced positive effect on the physical endurance of the animals, assessed in the grip test. For the 21 days of the experiment, this indicator increased by 26% in rats consuming EM, whereas in rats consuming CEM, the grip strength increased more significantly - by 42%. Consumption of CEM by animals increased the run time (33.8±1.4 min) and the distance covered (557±35 m) in the treadmill test before the exhaustion in comparison with similar indicators for animals that received EM (24.8±2.5 min and 365±50 m, respectively , p≤0.05). The obtained results indicate an increased resistance of animals treated with CEM to exhausting physical loads. Conclusion. The consumption of CEM by growing Wistar male rats increased more effectively their growth and physical endurance in comparison with animals treated with non-coagulated egg melange. These results show the prospective of the use of CEM as a functional food ingredient in specialized foods, enhancing physical endurance and working ability.

How the loss in academics and research occurs by stopping animal experimentation in medical curriculum

Use of animals in experimentation and research has always been a topic of great debate. Some express their strong support while others are against animal research practices and want their complete abolition.1 At present, there is a pill for every ill. Rapid advancement in the field of science and technology contributed in discovering cure and medications even for the rarest of the rare diseases. Most of the present day discoveries in medical science lay their foundation on animal experimentation. The use of drugs in clinical practice have been possible only after going through successful animal studies for safety, efficacy and toxicity.

The Frequency of Vaccine-Induced T-Cell Responses Does Not Predict the Rate of Acquisition after Repeated Intrarectal SIVmac239 Challenges in Mamu-B*08 + Rhesus Macaques

Approximately 50% of rhesus macaques (RMs) expressing the major histocompatibility complex class I (MHC-I) allele Mamu-B*08 spontaneously control chronic-phase viremia after infection with the pathogenic simian immunodeficiency virus mac239 (SIVmac239) clone. CD8+ T-cell responses in these animals are focused on immunodominant Mamu-B*08-restricted SIV epitopes in Vif and Nef, and prophylactic vaccination with these epitopes increases the incidence of elite control in SIVmac239-infected Mamu-B*08-positive (Mamu-B*08+ ) RMs. Here we evaluated if robust vaccine-elicited CD8+ T-cell responses against Vif and Nef can prevent systemic infection in Mamu-B*08+ RMs following mucosal SIV challenges. Ten Mamu-B*08+ RMs were vaccinated with a heterologous prime/boost/boost regimen encoding Vif and Nef, while six sham-vaccinated MHC-I-matched RMs served as the controls for this experiment. Vaccine-induced CD8+ T cells against Mamu-B*08-restricted SIV epitopes reached high frequencies in blood but were present at lower levels in lymph node and gut biopsy specimens. Following repeated intrarectal challenges with SIVmac239, all control RMs became infected by the sixth SIV exposure. By comparison, four vaccinees were still uninfected after six challenges, and three of them remained aviremic after 3 or 4 additional challenges. The rate of SIV acquisition in the vaccinees was numerically lower (albeit not statistically significantly) than that in the controls. However, peak viremia was significantly reduced in infected vaccinees compared to control animals. We found no T-cell markers that distinguished vaccinees that acquired SIV infection from those that did not. Additional studies will be needed to validate these findings and determine if cellular immunity can be harnessed to prevent the establishment of productive immunodeficiency virus infection.IMPORTANCE It is generally accepted that the antiviral effects of vaccine-induced classical CD8+ T-cell responses against human immunodeficiency virus (HIV) are limited to partial reductions in viremia after the establishment of productive infection. Here we show that rhesus macaques (RMs) vaccinated with Vif and Nef acquired simian immunodeficiency virus (SIV) infection at a lower (albeit not statistically significant) rate than control RMs following repeated intrarectal challenges with a pathogenic SIV clone. All animals in the present experiment expressed the elite control-associated major histocompatibility complex class I (MHC-I) molecule Mamu-B*08 that binds immunodominant epitopes in Vif and Nef. Though preliminary, these results provide tantalizing evidence that the protective efficacy of vaccine-elicited CD8+ T cells may be greater than previously thought. Future studies should examine if vaccine-induced cellular immunity can prevent systemic viral replication in RMs that do not express MHC-I alleles associated with elite control of SIV infection.

Prediction of Protocol Approval in a Mock Institutional Animal Care and Use Committee: Evaluation of Type of Research Protocol, Species, and Evaluator Characteristics

Research concerning using animal models that may ultimately benefit the health and well-being of human beings continues to receive substantial but not unequivocal support. Rather, considerable ambivalence driven by attitudes, personality characteristics, and misperceptions about animal research continue to exist. In the present study, individuals comprising various sectors of the academic community (undergraduate and graduate students, faculty, and staff) as well as recruits from the general population were presented with a mock research proposal that varied by goals and species. As part of a fictitious Institutional Animal Care and Use Committee (IACUC), the participants were asked to review the protocol and render a decision to either approve or reject the research proposal. In addition, the participants were queried about the perceived importance of the project, the suffering of the animals, and the amount of perceived scientific detachment from the animals. Lastly, the participants answered a series of items from a research-derived Perceptions about the Use of Animals Scale and the Emotional Intelligence Scale (EIS). Consistent with other research, female respondents were much less accepting of the research protocols than males. Protocol approval rates varied by the research objectives and the species, with research projects seen as having lower biomedical value such as psychology student training and the use of certain species (chimps & cats), generally receiving less support. The ethical issues associated with the use of animals in experiments is briefly considered as well as the need for additional messaging on role of animal research, particularly in the behavioral sciences.

Heat-Shock Protein 70-Mediated Heat Preconditioning Attenuates Hepatic Carbohydrate and Oxidative Disturbances in Rats With Type 1 Diabetes.

Heat preconditioning and heat-shock protein (HSP) synthesis have significant cytoprotective effects against the development of cellular injury caused by the application of a subsequent stressor, which were found to depend on the time period between the stressors. We aimed to determine the most efficient recovery time (6h or 24h) following heat-stress exposure and prior application of diabetic streptozotocin (STZ) on the moderation of carbohydrate and oxidative metabolic disturbances caused by diabetes. Experiment animals (Wistar rats) were exposed to acute heat stress at 41±1°C for 45min, followed by 6-h or 24-h recovery times at room temperature before sacrifice or STZ administration. Our findings indicate that acute heat stress with 6-h or 24-h recovery periods results in a significant rise in the hepatic heat-shock protein 70 (HSP70) levels (even more so after 24h), glycogen breakdown and stable glycemia, followed by reduced glycolytic and gluconeogenic activity (after 24h) (glucose-6-phosphatase, fructose-1,6-bisphosphatase); stimulates antioxidative activity (glutathione peroxidase, glutathione reductase) (after 6h); and decreases glutathione and catalase activity (after 24h). Heat preconditioning (with 6-h and 24-h recovery periods) prior to STZ-induced diabetes increases HSP70 levels and causes lower serum glucose levels, higher glycogen and glucose-6-phosphate levels, lower glucose-6-phosphatase levels and glycogen phosphorylase and hexokinase levels but also elevates glutathione reductase and glutathione peroxidase activity compared to untreated STZ animals. Based on our findings, heat preconditioning and HSP70 induction in rats with type 1 diabetes attenuates STZ-induced metabolic alterations in hepatic carbohydrate metabolism and oxidative states. These changes are more evident at 24h recovery post-acute heat stress, based on the most evident accumulation of HSP70 in this time frame.

Need for alternatives to animals in experimentation: An Indian perspective

Need for alternatives to animals in experimentation: An Indian perspective

A Study on the Experimental Animation and Movement Expression of Norman McLaren

A Study on the Experimental Animation and Movement Expression of Norman McLaren

A rational approach of early humane endpoint determination in a murine model for cholestasis_suppl

Reduction of animal suffering during in vivo experiments is usually ensured by continuously monitoring the health status using a score sheet and by applying humane endpoints. However, most studies do not evaluate the plausibility of score sheets and do not attempt to reduce the suffering of animals by determining earlier and, therefore, more humane endpoints. The present study uses data from BALB/cANCrl mice after bile duct ligation to retrospectively analyze which score sheet criteria are informative to determine humane endpoints. The performance of each single as well as com­binations of multiple animal welfare parameters was analyzed by a Cox proportional-hazards model followed by Harrell’s concordance index. The addition of behavioral parameters, such as burrowing activity, helped to define a more humane early endpoint for euthanizing these animals. Using this approach, we determined that a body weight loss of 10-20% combined with a reduction of burrowing activity by more than 79.4% was able to predict that these animals would die within two days. Thus, this approach successfully determined an earlier humane endpoint and will reduce the suffering of animals in future experiments. Application of such an approach or similar methods can contribute to the refinement of various animal experiments.

A rational approach of early humane endpoint determination in a murine model for cholestasis.

Reduction of animal suffering during in vivo experiments is usually ensured by continuously monitoring the health status using a score sheet and by applying humane endpoints. However, most studies do not evaluate the plausibility of score sheets and do not attempt to reduce the suffering of animals by determining earlier and, therefore, more humane endpoints. The present study uses data from BALB/cANCrl mice after bile duct ligation to retrospectively analyze which score sheet criteria are informative to determine humane endpoints. The performance of each single as well as com­binations of multiple animal welfare parameters was analyzed by a Cox proportional-hazards model followed by Harrell’s concordance index. The addition of behavioral parameters, such as burrowing activity, helped to define a more humane early endpoint for euthanizing these animals. Using this approach, we determined that a body weight loss of 10-20% combined with a reduction of burrowing activity by more than 79.4% was able to predict that these animals would die within two days. Thus, this approach successfully determined an earlier humane endpoint and will reduce the suffering of animals in future experiments. Application of such an approach or similar methods can contribute to the refinement of various animal experiments.

INTERNATIONAL LEGAL STANDARDS FOR CONDUCTING BIOMEDICAL EXPERIMENTS ON ANIMALS: STATUS AND PROSPECTS OF DEVELOPMENT

The article highlights the basic principles of the use of animals in biomedical research raised the main problems of vivisection. It also suggests specific steps to enhance the humanization of this process. The conclusions are the following: it is very important to prevent cruelty to animals in the context of resolving bioethical and legal problems associated with the implementation of the principle of humanism and the protection of animal rights. Modern science and the practice of preclinical and clinical tests should be involved into serious challenge in order to improve and universalize the process of medical and biological research technology in vitro. The purpose of the article is to study the main international legal principles of using animals in biomedical experiments, as well as to determine the main problems on this issue and to outline the ways to resolve them. The research material is a modern international regulatory framework that establishes the basic principles for the animals treatment. The methods of information retrieval, analysis, systematization, and generalization were used in this article. As it is well-known, human treatment of people begins with a human attitude towards animals. Nowadays the international community has adopted enough legal acts regulating the proper behavior with animals, including those specially cultivated for such studies (laboratory) when conducting biomedical experiments. Recently, both, in the national legislation of European countries and international legislation, there have been trends in the protection of both the general rights of animals as well as intensification of their protection in the field of biomedical research. It is imperative, both at the international and national levels, to adopt programs for development and support of scientific study of the in vitro biosystems introduction into the practice of toxicological studies. At the national level, it is necessary to criminalize the violation of international standards for conducting biomedical research using animals, strengthen other types of responsibility, and create a special system of state bodies responsible for the policy of using animals for biomedical purposes and exercising control in this area. Both, international and national legislation should impose a direct ban on the use of in vivo technologies in case of the possibility of using in vitro technologies.

Estrous Cycle Monitoring in Mice with Rapid Data Visualization and Analysis.

The estrous cycle provides a readout of reproductive health in female laboratory rodents, and estrous cycle stage can be an important physiological variable. Accurate assessment of estrous cycle stage is also important in producing timed pregnancies for developmental studies. Here, we provide a protocol for evaluation of estrous cycle stage through a minimally invasive procedure of acquiring cells lining the vaginal cavity and immediate microscopic visual assessment of these cells without drying or staining. When performed over several consecutive days, the pattern of progression through the four main stages of the estrous cycle, and disruptions to this pattern, can be determined. We also present software that enables more efficient cycle stage data analysis and pattern visualization. These protocols and tools will thus facilitate the incorporation of female animals in laboratory experiments and enhance the assessment of relationships between the reproductive cycle and overall physiology and behavior.

Effects of Red Meat Consumption on Histology of Coronary Arteries in Adult Albino Mice

Objective: To determine the effects of the red meat (Buffalo) on coronary arteries of adult albino male Mice. Study Design: Experimental study. Settings: Anatomy Department of Liaquat University of Medical and Health Sciences, Jamshoro in collaboration with animal house of Sindh Agriculture University Tando Jam. Duration: 6 months from January 2017 to July 2017. Methodology: Total 45 adult Albino male mice (laboratory male mice) of average 180–220 grams bodyweight was selected. Animals were housed (about 4-6 per cage) in a temperature-controlled room (22± 2°C) and at a humidity of 55%±5%, with a 12-hr light/dark cycle. Animals were divided into three groups as: group A (control), group B white meat (poultry) and group C (red meat). At the end of the experiment animals were sacrificed and hearts were taken from every animal as soon as possible and specimens were assessed for histopathology. Results: Mean cholesterol level was significantly higher among red meat consuming group as compared to control group (P- 0.001). Mean body weight was markedly higher among red meat consuming group in contrast to control group; p-values were quite significant. Total 6.66% mice suffered in red meat consuming group and out of them 3.34% died. Conclusion: It was concluded that red meat consumption is associated to a higher risk of cholesterol elevation and mortality, without any histological alteration.

Protective action of a modified fragment of galanine in rats with doxorubicin-induced heart failure

The use of the anticancer drug doxorubicin (Dox) is limited due to its cardiotoxic effect. Using the method of automatic solid-phase peptide synthesis, we obtained a synthetic agonist of galanin receptors GalR1-3 [RAla14, His15]-galanine (2-15) (G), exhibiting cardioprotective properties. It was purified by high performance liquid chromatography (HPLC). The homogeneity and structure of the peptide was confirmed by HPLC, 1H-NMR spectroscopy and mass spectroscopy. The purpose of this study was to study the effect of G on the metabolism and cardiac function of rats with chronic heart failure (CHF) caused by Dox. Experiments were performed using male Wistar rats weighing 280-300 g. The control group of animals (C) was intraperitoneally treated with saline for 8 weeks; the doxorubicin group (D) of rats was intraperitoneally treated with Doх; the group of Doх + peptide G (D+G) received intraperitoneally injections of Doх and subcutaneously injections of peptide G; the peptide G group (G) was subcutaneously treated with G. At the beginning and at the end of the study, the concentration of thiobarbituric acid reactive substances (TBARS) and the activity of creatine kinase-MB (CK-MB) were determined in blood plasma; the animals were weighed, and cardiac function was assessed using echocardiography. At the end of the experiments, the hearts were used for determination of metabolites and assessment of oxidative phosphorylation in mitochondria. After 8-week treatment, animals of group D were characterized by severe heart failure, the lack of weight gain and an increase in plasma TBARS concentration and CK-MB activity. These disorders were accompanied by a decrease in the content of myocardial high-energy phosphates, a reduction inmitochondrial respiratory parameters, accumulation of lactate and glucose in the heart, and disturbances in the metabolism of alanine and glutamic and aspartic acids. Coadministration of G and Dox prevented the increase in plasma CK-MB activity and significantly reduced the plasma TBARS concentration. At the end of the experiments animals of group D+G had higher myocardial energy state and the respiratory control index of mitochondria than animals of group D, there was a decrease in anaerobic glycolysis and no changes in the amino acid content compared to the control. The peptide G significantly improved the parameters of cardiac function and caused weight gain in animals of group D+G in comparison with these parameters in group D. The obtained results demonstrate the ability of a novel agonist of galanin receptors GalR1-3 to attenuate Dox-indiced cardiotoxicity.

Testing of delivery system for transcatheter mitral valve implantation

Aim. The aim of the study was to evaluate a prototype of a delivery system for transcatheter mitral valve replacement in vitro and in laboratory animal implantation. Methods. The prototypes of the delivery system and transcatheter mitral valve prosthesis were evaluated in vitro in an isolated pig heart using transapical access. In an experiment on a large laboratory animal implantation was performed using transatrial access.Results. It was found out that the prototype of the delivery system allows to adequately deliver and release the transcatheter prosthesis in implantation zone using transatrial and transapical approaches without frame deformation and valve dysfunction. Conclusion. The delivery system prototype for transcatheter mitral valve replacement demonstrated satisfactory characteristics during in vitro experiment and large laboratory animal implantation. Received 26 November 2018. Revised 17 December 2018. Accepted 21 December 2018. Funding: The study was carried out with the support of a grant of the Russian Science Foundation No. 16-15-10315. Conflict of interest: Author declare no conflict of interest. Author contributionsConception and study design: I.Y. Zhuravleva Data collection and analysis: T.P. Timchenko, M.A. Ovcharov, E.V. Boyarkin Drafting the article: R.M. Sharifulin, I.S. Zykov Critical revision of the article: A.V. Bogachev-Prokophiev, A.M. KaraskovFinal approval of the version to be published: R.M. Sharifulin, A.V. Bogachev-Prokophiev, I.Y. Zhuravleva, T.P. Timchenko, I.S. Zykov, E.V. Boyarkin, M.A. Ovcharov, A.M. Karaskov

Patents, animal experiments and animal sentience—where do we currently stand?

At present, the European Union (EU), and therefore the UK, recognizes non-human animals (hereafter ‘animals’) as ‘sentient beings’.1 In the wake of the Brexit referendum, there has been much political talk over what will happen to this sentience provision once the UK leaves the EU.2 In December 2017, the UK Government announced that the sentience of animals would continue to be recognized once the UK leaves the EU; however, it is unclear what form any such protection would take. On 7 August 2018, the UK Government stated that it would continue to work on the issue of animal sentience ‘with the intention of introducing any necessary legislation before the UK leaves the EU’.3 This article looks at the current UK legal framework regulating the use of animals in the life sciences sector, focussing on the patenting of animals and the use of animals in scientific experiments relating to medicinal products for humans. Where does our legal landscape currently stand and how far, if at all, does the sentience provision limit the use of animals in the life sciences? And, will the regulatory landscape change post-Brexit?

The influence of cholinergic drugs on EEG of the brain of the castrated rabbit males

Aim. We investigated the influence of various cholinoceptive drugs on spontaneous activity of a brain at the intact rabbit and in the conditions of deficit of gonadal hormones, and also studied of reciprocal influence of cholinergic drugs on changes of character of a range of EEG at the intact and castrated rabbits.
 Methods. Our researches were carried out on 32 rabbit males of breed the Chinchilla. Bipolar nichrome electrodes implanted to rabbits by stereotactic operaition into a caudate nucleus, a hippocampus and a reticular formation of a mesencephalon and also cortical monopolar chlorsilver electrodes with a diameter of 1 mm - to the optic and frontal area of cortex. Registration of EEG carried out in a shielded chamber with use of the electroencephalograph-analyzer EEGA-21/26 “Encephalan-131-03”. The averaged EEG range power was analyzed with a 60 s recording epoch. In 3 weeks after implantation of electrodes we studied the influence a number of cholinergic drugs on spontaneous EEG: M-cholinolytic metamizyl (1 mg/kg i.p.), N-cholinolytic gangleronum (5 mg/kg i.p.), inhibitor of acetylcholinesterase (AChE) galantamine (0.5 mg/kg i.p.). Registration was carried out in 1, 2 and 3 hours after an injection. Under the combined investigation of preparation galantamine was entered in 20 minutes after an injection of cholinolytics. Then, we carried out removal of a testis at rabbits — males under etherization. The spontaneous electric activity of a brain of that rabbits and influence of cholinergic drugs was registered in 30 days after operation of bilateral gonadectomy.
 Result. The gonadectomy of Chinchilla rabbits causes the deceleration of EEG range power twice in comparison with intact animals in a chronic experiment. The analysis of influence of cholinoceptive substances on EEG showed that the most sensitive to the change of balance between M- and N-cholinoreceptors are cerebral cortex and caudate nucleus. The intensity of the activating effect accompanying blockade of M-cholinoreceptors is higher in cortical structures, than in subcortical nuclei in all animals. The reaction of caudate nucleus to the blockade of M-cholinoreceptors is the most sensitive among subcortical nuclei. It “answers” with increase in EEG range power. The blockade of N-cholinoreceptors in this structure after insignificant potentiating is followed by decrease of EEG range power. The activity of hippocampus is least dependent on the level of androgens in organism.
 Conclusions. The analysis of influence of cholinoceptive substances on spontaneous activity of a brain showed that the most sensitive to change of balance between M-cholinoreceptors and H-cholinoreceptors were a cerebral cortex and a caudate nucleus. As at the intact as the castrated animals the expressiveness of the activating effect accompanying blockade of M-cholinoreceptors is higher in cortical structures than in subcortical nuclei.

Does the stress of laboratory life and experimentation on animals adversely affect research data? A critical review.

Recurrent acute and/or chronic stress can affect all vertebrate species, and can have serious consequences. It is increasingly and widely appreciated that laboratory animals experience significant and repeated stress, which is unavoidable and is caused by many aspects of laboratory life, such as captivity, transport, noise, handling, restraint and other procedures, as well as the experimental procedures applied to them. Such stress is difficult to mitigate, and lack of significant desensitisation/habituation can result in considerable psychological and physiological welfare problems, which are mediated by the activation of various neuroendocrine networks that have numerous and pervasive effects. Psychological damage can be reflected in stereotypical behaviours, including repetitive pacing and circling, and even self-harm. Physical consequences include adverse effects on immune function, inflammatory responses, metabolism, and disease susceptibility and progression. Further, some of these effects are epigenetic, and are therefore potentially transgenerational: the biology of animals whose parents/grandparents were wild-caught and/or have experienced chronic stress in laboratories could be altered, as compared to free-living individuals. It is argued that these effects must have consequences for the reliability of experimental data and their extrapolation to humans, and this may not be recognised sufficiently among those who use animals in experiments.

Olfactory discrimination between litter mates by mothers and alien adult cats: lump or split?

Mother cats can discriminate between their own and alien kittens using kittens' body odour. Here we ask whether they can also distinguish between body odours of kittens from the same litter. We conducted three experiments using the habituation-dishabituation technique with the odour of 1- and 7-week-old kittens of both sexes. In Experiment 1, we found no evidence that mothers discriminated among their own kittens of either age when presented three times with the odour of one individual (habituation trials) and then with the odour of a different individual (dishabituation or discrimination trial), even when the donor kittens were of different sex. In Experiment 2, alien adults of both sexes distinguished between 7 but not between 1-week-old litter mates. In Experiment 3, mothers distinguished between unknown litter mates in a similar and age-dependent manner to the animals of Experiment 2. We conclude that litter mates possess individual odour signatures that can be discriminated by adult cats, that these cues take some time to develop, but are not discriminated by their own mother, at least not during the pre-weaning period. Mothers possibly perceive and respond to a learned "nest"/litter odour shared by all litter mates or categorize the individual odours of their kittens as belonging to an "own kitten" category. That mothers did not discriminate between the odours of their own kittens but did so between individual kittens of alien litters suggests that different levels of processing olfactory information exist in mothers' ability to cognitively partition and differentially respond to such odours.

Experimental poisoning by Brachiaria decumbens in rabbits

ABSTRACT: Brachiaria spp. are important sources of forage for ruminants in Brazil, due to the easy cultivation, good resistance to drought, good adaptation to different soils and low maintenance cost. However, the ingestion of this grass has been related to photosensitization outbreaks in cattle and sheep with significant economic losses. The hepatotoxic effects related to the ingestion of grass are the formation of crystals and foamy macrophages due to the accumulation of toxic metabolites. The use of cattle and sheep in experiments involving the plant presents several obstacles in the ethical, economic and animal management. The objective of this study was to evaluate the sensitivity of rabbits as an experimental model for B. decumbens poisoning. Two experiments were carried out. In Experiment 1 four rabbits received the fresh plant in daily doses of 10, 20, 40 and 80g/kg body weight for 120 days. In Experiment 2 three rabbits received the fresh plant in amounts of 500g daily with duration of 210 days. The animals of Experiment 1 showed no clinical signs and no macroscopic and microscopic changes characteristic of B. decumbens poisoning. In Experiment 2 the animals also showed no clinical signs or significant macroscopic alterations. Histological analysis showed isolated foamy macrophages or present in random groups of cells in the liver and mesenteric lymph nodes. Samples of liver and mesenteric lymph nodes of the rabbits of Experiment 2 were submitted to the lectin-histochemistry technique. The WGA, sWGA and RCA lectins showed reactivity in foamy macrophages in both organs. This is the first study of our knowledge that demonstrates histopathological lesions caused expetimentally by Brachiaria spp. in rabbits, demonstrating its potential as an animal model.

О ВОЗМОЖНОСТИ ИСПОЛЬЗОВАНИЯ ЛАБОРАТОРНЫХ ЖИВОТНЫХ В ЭКСПЕРИМЕНТАЛЬНОЙ ХИРУРГИИ

After analyzing the literature, we established general patterns and specificity using various animal species to simulate the reaction of certain organs and body systems. In addition, the specifics of such studies from the ethical point of view, as well as the human dimension in the experiment on animals, are considered. As a result of studying literature sources, it was revealed that, unfortunately, at the present stage of the development of science, it’s not possible to completely replace experiments on animals with computational techniques and modeling. However, for ethical reasons, experiments are performed using means that reduce the suffer- ing of animals, such as general anesthesia, local anesthesia, proper animal care, that is eliminating senseless cruelty towards them. In order to avoid cruelty to animals, the issues of laboratory research with their participation regulate the legislation, as well as control by such independent bodies, dealing with problems of ethics and morality as an ethical committee. The basic motives for using animals in experiments is the desire to save lives, in a timely manner to identify and prevent undesirable consequences of applying a new technique for treating diseases or making new drugs