Jann Hau

Effect of metabolic cage housing on immunoglobulin A and corticosterone excretion in faeces and urine of young male rats

Six 8‐week‐old Sprague‐Dawley rats were studied for 9 days divided into three periods of 3 days each: before transferral to metabolism cages, during metabolic cage housing and after return to their home cages. Faeces were collected daily when the animals were housed in their home cages and every 6 h when the animals were housed in metabolic cages during which time urine was also collected every 6 h. The rate of weight gain was slightly reduced during the 3 days in metabolic cages and the animals produced significantly larger amounts of faeces when housed in metabolic cages than when housed in their home cages. The total faecal excretion of corticosterone (nanograms excreted per hour per kilogram body weight) and immunoglobulin A (IgA) (milligrams excreted per hour per kg body weight) quantified by enzyme‐linked immunosorbent assays (ELISAs) exhibited a clear diurnal rhythm in the metabolic cage. Urinary excretions of corticosterone and IgA also followed a clear diurnal cycle. The mean daily amounts of corticosterone excreted were not significantly affected by cage change and by housing in metabolic cages. However, the excretion of faecal IgA was significantly reduced during the 3 days after the period in metabolic cages. Taken together the results indicate that metabolic cage housing is mildly stressful for young adult male rats.

An overview of surveys on how people view animal experimentation: some factors that may influence the outcome

Many factors may influence the outcome of surveys on how people view the use of animals in research. Some aspects are related to the instrument used, whereas others are related to the characteristics of the respondents. Conducted in Western countries, the study is primarily a review of 56 surveys targeting scientists, students, and the public. Surveys were obtained from searching online databases and reference lists, or directly from authors whose surveys were not otherwise available. Factors related to the instrument listed include the questionnaire used and wording of questions. Factors related to the respondent include age, gender, upbringing, religion, knowledge, education, and practical experience. Results demonstrate that there was great discrepancy in acceptance/opposition estimations reported in different surveys. It is concluded that interpretation and comparison of results from different surveys should be made with caution.

Faecal corticosterone and immunoglobulin A in young adult rats

Quantitative analyses of relevant molecules in faeces may have potential as future non-invasive measures of stress. This study examined levels of faecal corticosterone and immunoglobulin A (IgA) in young adult rats and how these levels varied according to age, gender and time of day. Faecal samples were collected from 40 young adult rats (7 weeks old, n = 20 and 10 weeks old, n = 20) of both sexes from two time windows: day and night. The concentrations of corticosterone and IgA were measured by ELISAs following organic solvent extraction and aqueous extraction, respectively, of the molecules from faecal pellets. The production of faeces per time unit was higher in males than in females, and linear correlations were found between the faecal concentrations of corticosterone and IgA and total amounts of the respective molecules excreted in faeces per kg body weight per hour. In all further analyses the levels of the two molecules were calculated as amounts secreted per kg of body weight per hour. There was no gender difference between females and males in the production of corticosterone and IgA, but 7-week-old animals excreted significantly higher amounts of both molecules than did 10-week-old rats. The levels of IgA excreted by female rats were higher in the evening than in the morning, and male rats excreted higher concentrations of corticosterone in the morning than in the evening.

Adrenal cortex and stomach lesions associated with stress in wild male African green monkeys (Cercopithecus aethiops) in the post-capture period

The objective of this study was to look for early pathological changes in stress target organs, adrenal glands, and stomachs in captured wild African green monkeys (AGMs). Three wild‐caught male AGMs and seven singly housed wild AGMs were euthanized on day 1 and day 45 post‐capture, respectively, and compared with four wild males euthanized with a rifle as controls. Morphometric analyses of the adrenal cortices and the cortical zones were done using an image analyzer. By day 45, the confined animals were clinically healthy, but had lost 47% mean body weight despite ad libitum feeding. The width of zona fasciculata in the controls was significantly smaller compared with that of 45‐day monkeys (P<0.05). Numerous acidophilic, hyperplastic and hypertrophic cells were present in the zona fasciculata of the 1‐day confined AGMs. In the 45‐day monkeys, there was glandular hyperplasia in the zona glomerulosa and the acini were distended and vacuous; yellow, granular pigmentation was distributed in the zona fasciculata. Acute stomach lesions represented by petechiation were seen in one monkey on day 1. Deep, circular, mucosal erosions, one to five in number and measuring from 0.5 to 1 mm in diameter, were present in three monkeys on day 45 post‐capture. There were no adrenal cortex or stomach lesions in the rifle‐shot monkeys. In conclusion, pathological lesions in the adrenal glands, and stomachs of the wild AGMs and weight loss occurred within the initial 45‐day period following capture and confinement.

Effect of Subcutaneous Injection and Oral Voluntary Ingestion of Buprenorphine on Post-Operative Serum Corticosterone Levels in Male Rats

Background: Adequate peri-operative analgesia may reduce post-operative stress response and improve recovery in laboratory animals. We have established a method involving repeated automated blood sampling, allowing quantification of serum corticosterone levels in rats for stress assessment without stress-inducing handling or restraint. In the present study, the effects of the commonly used route of buprenorphine administration (0.05 mg/kg injected subcutaneously) were compared with oral administration (0.4 mg/kg mixed with Nutella® and orally administered by voluntary ingestion) in male Sprague-Dawley rats. Methods: A catheter was placed in the jugular vein and attached to an Accusampler® for automated blood sampling. During 96 h after surgery, blood was collected at specified time points. Pre- and post-operative body weights and water consumption were registered. Results: Buprenorphine significantly suppressed levels of circulating corticosterone after the oral but not after the subcutaneous treatment. Both buprenorphine treatments had a positive impact on maintenance of body weight and water consumption, compared to the control group that received no buprenorphine. Conclusion: The present investigation suggests that oral voluntary ingestion ad libitum is an efficacious, convenient and non-invasive way of administering peri-operative buprenorphine to rats, as judged by corticosteroid response and effects on body weight and water consumption.

PHYSIOLOGIC MANIFESTATIONS OF STRESS FROM CAPTURE AND RESTRAINT OF FREE-RANGING MALE AFRICAN GREEN MONKEYS (CERCOPITHECUS AETHIOPS)

Abstract Adrenal gland weights, stomach mucosal lesions, and morning serum cortisol and prolactin levels were measured in 15 juvenile and adult male African green monkeys (Cercopithecus aethiops) that were shot by a hunter, euthanized after 24 hr of captivity, or euthanized after 45 days of captivity and intermittent blood sampling. Hormone levels were measured in seven additional males that had been in captivity for 7 mo. Mean serum cortisol concentrations were significantly lower in free-ranging wild monkeys at the time they were shot than in the monkeys after 1 day in captivity. Cortisol concentrations were significantly higher in wild-caught monkeys on the day after capture than they were in the same animals after 18 and 26 days of captivity. Cortisol concentrations were also significantly higher in the wild-caught monkeys 18 days after capture than in the laboratory-habituated monkeys in captivity for 7 mo. Mean prolactin concentration was significantly lower in the wild-caught monkeys on day 2 after capture, and the levels increased gradually to 45 days in captivity and was highest in monkeys that had been captive for 7 mo.

Surveys on attitudes towards legalisation of euthanasia: importance of question phrasing

Aim: To explore whether the phrasing of the questions and the response alternatives would influence the answers to questions about legalisation of euthanasia. Methods: Results were compared from two different surveys in populations with similar characteristics. The alternatives “positive”, “negative”, and “don’t know” (first questionnaire) were replaced with an explanatory text, “no legal sanction”, four types of legal sanctions, and no possibility to answer “don’t know” (second questionnaire). Four undergraduate student groups (engineering, law, medicine, and nursing) answered. Results: In the first questionnaire (nu200a=u200a684) 43% accepted euthanasia (range 28–50%), 14% (8–33%) did not, and 43% (39–59%) answered “don’t know”. Two per cent of the respondents declined to answer. In comparison with previous surveys on attitudes to euthanasia the proportion of “don’t know” was large. The results of the second questionnaire (nu200a=u200a639), showed that 38% favoured “no legal prosecution” (26–50%). However, 62% (50–74%) opted for different kinds of legal sanctions, and two of four groups expressed significantly different views in the two surveys. A proportion of 10% declined to answer the second questionnaire. Conclusion: An introduction of an explanatory text and a wider range of response alternatives produced differences between the results of the two surveys conducted.

Development and validation of a sensitive ELISA for quantification of secretory IgA in rat saliva and faeces

Non-invasive measures of immunological markers are an attractive means of stress assessment in laboratory animals. Salivary IgA has been used successfully as a stress marker in the human, and several reports indicate the potential of secretory IgA as a non-invasive measure of stress in animals. The present paper describes the development of an ELISA using commercially available components for the quantification of rat IgA and validation of this assay for the quantification of rat secretory IgA in saliva and faeces. The concentration of IgA in rat saliva varied significantly between duplicate samples obtained from individual rats, and the viscosity and small total volume of rat saliva gave unsatisfactory results for IgA. Faecal IgA was present in high concentrations, and duplicate samples varied by only 2-3%. However, faecal IgA seemed less stable than IgA in other biological compartments, and this finding must be taken into consideration when using quantitative measurements of IgA as a marker of mucous humoral immune status.

Stress in cynomolgus monkeys (Macaca fascicularis) subjected to long-distance transport and simulated transport housing conditions

The stress associated with transportation of non-human primates used in scientific research is an important but almost unexplored part of laboratory animal husbandry. The procedures and routines concerning transport are not only important for the animals physical health but also for their mental health as well. The transport stress in cynomolgus monkeys (Macaca fascicularis) was studied in two experiments. In Experiment 1, 25 adult female cynomolgus monkeys were divided into five groups of five animals each that received different diets during the transport phase of the experiment. All animals were transported in conventional single animal transport cages with no visual or tactile contact with conspecifics. The animals were transported by lorry for 24 h at ambient temperatures ranging between 20°C and 35°C. Urine produced before, during and after transport was collected and analysed for cortisol by enzyme-linked immunosorbent assay (ELISA). All monkeys exhibited a significant increase in cortisol excretion per time unit during the transport and on the first day following transport. Although anecdotal reports concerning diet during transport, including the provision of fruits and/or a tranquiliser, was thought likely to influence stress responses, these were not corrobated by the present study. In Experiment 2, behavioural data were collected from 18 cynomolgus macaques before and after transfer from group cages to either single or pair housing, and also before and after a simulated transport, in which the animals were housed in transport cages. The single housed monkeys were confined to single transport cages and the pair housed monkeys were kept in their pairs in double size cages. Both pair housed and singly housed monkeys showed clear behavioural signs of stress soon after their transfer out of their group cages. However, stress-associated behaviours were more prevalent in singly housed animals than in pair housed animals, and these behaviours persisted for a longer time after the simulated transport housing event than in the pair housed monkeys. Our data confirm that the transport of cynomolgus monkeys is stressful and suggest that it would be beneficial for the cynomolgus monkeys to be housed and transported in compatible pairs from the time they leave their group cages at the source country breeding facility until they arrive at their final laboratory destination in the country of use.

The refining influence of ethics committees on animal experimentation in Sweden.

Mandatory scrutiny of projects by animal ethics committees was introduced in Sweden in 1979. The present study investigated the minutes of meetings held between 1989 and 2000 at which consideration of applications for experimental work in animals resulted in requests for modification (n = 3607). 18.1% of the applications received were approved only after modifications. The majority of the changes requested may be classified as Refinement. The most common requests were for improvement of project design, euthanasia method and housing and husbandry. There was a relative increase in modifications requested by the committees related to anaesthesia, choice of licensed supervisor and the need for licenses or informed consent from animal owners during the period investigated. There was a relative decrease in modifications related to euthanasia, housing and husbandry, and general endpoint assertions. The results suggest that the work of the committees may be perceived as an ongoing process, since several of the applications for which modification was requested were projects that had been approved on a previous occasion but were now up for renewal. In order to have maximal influence on the refinement of scientific protocols it is important that the scientists in the committees are continuously updated on developments in laboratory animal science.