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Individualized Housing Modifies the Immune–Endocrine System in CD1 Adult Male Mice. Animals (Basel) 2023; 13:ani13061026. [PMID: 36978567 PMCID: PMC10044133 DOI: 10.3390/ani13061026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/08/2023] [Accepted: 03/09/2023] [Indexed: 03/14/2023] Open
Abstract
In the last years, different research groups have made considerable efforts to improve the care and use of animals in research. Mice (Mus musculus) are the most widely used animal species in research in the European Union and are sociable and hierarchical creatures. During experiments, researchers tend to individualize males, but no consideration is given to whether this social isolation causes them stress. The aim of this study was, therefore, to explore whether 4 weeks of social isolation could induce changes in different physiological parameters in adult Crl:CD1(ICR) (CD1) males, which may interfere with experimental results. Body weight, blood cells, and fecal corticosterone metabolites levels were the analyzed parameters. Blood and fecal samples were collected at weeks 1 and 4 of the experimental procedure. Four weeks of single housing produced a significant time-dependent decrease in monocytes and granulocytes. Fecal corticosterone metabolite levels were higher in single-housed mice after 1 week and then normalized after 4 weeks of isolation. Body weight, red blood cells, and platelets remained unchanged in both groups during this period. We can, therefore, conclude that social isolation affects some immune and endocrine parameters, and that this should be taken into account in the interpretation of research data.
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Russell A, Copio JN, Shi Y, Kang S, Franklin CL, Ericsson AC. Reduced housing density improves statistical power of murine gut microbiota studies. Cell Rep 2022; 39:110783. [PMID: 35545042 PMCID: PMC9161176 DOI: 10.1016/j.celrep.2022.110783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 12/28/2021] [Accepted: 04/13/2022] [Indexed: 11/25/2022] Open
Abstract
The gut microbiome of humans and animals is critical to host health. Mice are used to investigate the microbiome and its influences; however, the predictive value of such studies is hindered by cage effects due to coprophagy. Our objectives were to evaluate the influence of cage density on the statistical power to detect treatment-dependent effects of a selective pressure on microbiome composition. C57BL/6 mice were separated into groups of 2 or 4 mice per cage and then assigned to groups receiving enrofloxacin, broad-spectrum antibiotics, or control. Fecal samples were collected at weeks 0, 1, and 4, along with contents of the jejunum and cecum. Bacterial DNA analysis examined microbiome richness, diversity, and variability within and between cages. Statistical analyses reveal that reduced housing density consistently results in comparable susceptibility to antibiotics, reduced cage effects, and increased statistical power to detect treatment-associated effects, justifying the practice of reduced housing density.
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Affiliation(s)
- Amber Russell
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65201, USA
| | - Joanna N Copio
- College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210 USA
| | - Yushu Shi
- Department of Statistics, College of Arts and Sciences, University of Missouri, Columbia, MO 65201 USA
| | - Sumin Kang
- Department of Statistics, College of Arts and Sciences, University of Missouri, Columbia, MO 65201 USA
| | - Craig L Franklin
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65201, USA; University of Missouri Metagenomics Center, University of Missouri, Columbia, MO 65201 USA; Mutant Mouse Resource and Research Center, University of Missouri, Columbia, MO 65201 USA
| | - Aaron C Ericsson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65201, USA; University of Missouri Metagenomics Center, University of Missouri, Columbia, MO 65201 USA; Mutant Mouse Resource and Research Center, University of Missouri, Columbia, MO 65201 USA.
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3
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Lee CR, Chen A, Tye KM. The neural circuitry of social homeostasis: Consequences of acute versus chronic social isolation. Cell 2021; 184:1500-1516. [PMID: 33691140 PMCID: PMC8580010 DOI: 10.1016/j.cell.2021.02.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/29/2021] [Accepted: 02/09/2021] [Indexed: 11/22/2022]
Abstract
Social homeostasis is the ability of individuals to detect the quantity and quality of social contact, compare it to an established set-point in a command center, and adjust the effort expended to seek the optimal social contact expressed via an effector system. Social contact becomes a positive or negative valence stimulus when it is deficient or in excess, respectively. Chronic deficits lead to set-point adaptations such that reintroduction to the previous optimum is experienced as a surplus. Here, we build upon previous models for social homeostasis to include adaptations to lasting changes in environmental conditions, such as with chronic isolation.
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Affiliation(s)
- Christopher R Lee
- The Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Alon Chen
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Kay M Tye
- The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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Seyidoglu N, Gurbanli R, Köseli E, Cengiz F, Aydin C. The effects of Spirulina (Arthrospira) platensis on morphological and hematological parameters evoked by social stress in male rats. ACTA ACUST UNITED AC 2019. [DOI: 10.30704/http-www-jivs-net.544154] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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5
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Engel JM, Widowski TM, Tilbrook AJ, Butler KL, Hemsworth PH. The effects of floor space and nest box access on the physiology and behavior of caged laying hens. Poult Sci 2019; 98:533-547. [PMID: 30165652 DOI: 10.3382/ps/pey378] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/23/2018] [Indexed: 11/20/2022] Open
Abstract
Confinement housing appears to be at the forefront of concern about laying hen welfare. This experiment examined the effects of floor space during rearing (315 or 945 cm2/bird) and adulthood (542 or 1648 cm2/bird) and access to a nest box on the welfare of caged laying hens. Measurements of the normality of biological functioning, such as plasma, egg albumen and yolk and fecal corticosterone concentrations, and heterophil to lymphocyte ratios, behavioral time budgets, mortality and efficiency of productivity, and measurement of hen preferences, such as choice behavior in Y maze tests, were used to assess hen welfare. There were no effects of treatment on physiological measurements. Hens given less space during adulthood spent less time mobile, inedible pecking, drinking, and preening and spent more time resting and feed pecking and sitting (P < 0.05). Hens with access to a nest box spent more time resting (P = 0.046) and less time sham dust bathing (P = 0.044) than hens without access to a nest box. There were no effects of space allowance on choice behavior for space or a nest box over food; however, hens with access to a nest box chose the nest box over food more than hens without access to a nest box (P = 0.0053). The present experiment provides no convincing evidence that either reducing space allowance in adulthood from 1648 to 542 cm2/bird or eliminating access to a nest box results in disruption of biological function. Less space and no access to a nest box did not increase the choice for more space or a nest box, respectively, over food in the preference tests. However, reduced floor space reduced behavioral freedom and denying access to a nest box eliminated the opportunity for the motivated behavior of laying their eggs in a discrete enclosed nest box, both of which presumably provide hens with the opportunity for positive affective experiences.
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Affiliation(s)
- J M Engel
- Animal Welfare Science Centre, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia
| | - T M Widowski
- Department of Animal and Poultry Science, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - A J Tilbrook
- Centre for Animal Science, University of Queensland, St Lucia, Queensland, 4072, Australia
| | - K L Butler
- Biometrics Group, Department of Economic Development, Jobs, Transport & Resources, Hamilton, VIC 3030, Australia
| | - P H Hemsworth
- Animal Welfare Science Centre, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia
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6
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Dai X, Zhou LY, Cao JX, Zhang YQ, Yang FP, Wang AQ, Wei WH, Yang SM. Effect of Group Density on the Physiology and Aggressive Behavior of Male Brandt's Voles ( Lasiopodomys brandtii). Zool Stud 2018; 57:e35. [PMID: 31966275 PMCID: PMC6517712 DOI: 10.6620/zs.2018.57-35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 06/21/2018] [Indexed: 11/18/2022]
Abstract
Xin Dai, Ling-Yu Zhou, Jie-Xia Cao, Yan-Qi Zhang, Feng-Ping Yang, Ai-Qin Wang, Wan-Hong Wei, and Sheng-Mei Yang (2018) Population density is well known to influence animal physiology and behavior. How population density affects the aggressive behavior of the Brandt's vole (Lasiopodomys brandtii) is, however, little known. The aim of this study was to investigate the effect of group density on physiologic responses and aggressive behavior of male Brandt's voles and their potential underlying neuro-mechanism. The results show that increasing group density led to elevated serum corticosterone levels and increased spleen weight; it also induced more male-male aggressive behavior. By contrast, it had a negative effect on body growth and the weight of testis and epididymis. Aging also increased male-male aggressive behavior. Higher density reduced mRNA levels of tryptophan hydroxylase 2 (TPH2), 5-hydroxytryptamine receptor 1A (5HT1A), and 5-hydroxytryptamine receptor 1B (5HT1B) in the amygdala and the dorsal raphe nucleus (DRN). Our results demonstrate that higher population density can intensify stress reactions and male-male aggressive behavior in Brandt's voles at the price of inhibiting body growth and reproduction. Serotonergic systems in the amygdala and the DRN may take part in the control of aggressive behavior among male voles. Our results provide novel insights into the neuro-mechanism underlying the influence of population density on aggressive behavior in Brandt's vole, and imply that aggressive behavior may play an important role in the population fluctuation of the animal.
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Affiliation(s)
- Xin Dai
- College of Bioscience and Biotechnology, Yangzhou
University, 48 East Wenhui Road, Yangzhou 225009, P.R. China
| | - Ling-Yu Zhou
- College of Bioscience and Biotechnology, Yangzhou
University, 48 East Wenhui Road, Yangzhou 225009, P.R. China
| | - Jie-Xia Cao
- College of Bioscience and Biotechnology, Yangzhou
University, 48 East Wenhui Road, Yangzhou 225009, P.R. China
| | - Yan-Qi Zhang
- College of Bioscience and Biotechnology, Yangzhou
University, 48 East Wenhui Road, Yangzhou 225009, P.R. China
| | - Feng-Ping Yang
- College of Bioscience and Biotechnology, Yangzhou
University, 48 East Wenhui Road, Yangzhou 225009, P.R. China
| | - Ai-Qin Wang
- College of Bioscience and Biotechnology, Yangzhou
University, 48 East Wenhui Road, Yangzhou 225009, P.R. China
| | - Wan-Hong Wei
- College of Bioscience and Biotechnology, Yangzhou
University, 48 East Wenhui Road, Yangzhou 225009, P.R. China
| | - Sheng-Mei Yang
- College of Bioscience and Biotechnology, Yangzhou
University, 48 East Wenhui Road, Yangzhou 225009, P.R. China
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7
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Hemsworth PH, Morrison R, Tilbrook AJ, Butler KL, Rice M, Moeller SJ. Effects of varying floor space on aggressive behavior and cortisol concentrations in group-housed sows1. J Anim Sci 2016; 94:4809-4818. [DOI: 10.2527/jas.2016-0583] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Gaskill BN, Pritchett-Corning KR. The Effect of Cage Space on Behavior and Reproduction in Crl:CD1(Icr) and C57BL/6NCrl Laboratory Mice. PLoS One 2015; 10:e0127875. [PMID: 26020792 PMCID: PMC4447268 DOI: 10.1371/journal.pone.0127875] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 04/20/2015] [Indexed: 11/18/2022] Open
Abstract
Recommendations for the amount of cage space required for female mice with litters were first made in the 2011 Guide for the Care and Use of Laboratory Animals. We hypothesized that if a difference in mouse behavior and reproduction exists within the limits of commercially available caging, this difference would be detected between the smallest and largest cages. C57BL/6NCrl and Crl:CD1(Icr) breeding mice were randomly assigned to a cage treatment: LP 18790 (226 cm2); A RC1 (305 cm2); A N10 (432 cm2); T 1291 (800 cm2) and a breeding configuration: single (male removed after birth); pair (1 male + 1 female); or trio (1 male + 2 females) in a factorial design for 12 weeks. All cages received 8-10 g of nesting material and nests were scored weekly. Pups were weaned between post-natal day 18 and 26 and were weighed at weaning. Adult behavior and location in the cage were recorded by scan samples every 30 min over 48 hr of video recorded on PND 0-8 and PND 14-21 when pups were in the cage. Press posture and play behavior were recorded by 1/0 sampling method. Cage space did not significantly alter typical reproductive measures. Pups in the smallest cage played less than in the other cages. Adults in the smallest cage displayed more press posture than in the two largest cages. Mice in the largest cage spent more time under the feeder than in other areas of the cage. Nest score was also the highest in the largest cage. Housing breeding groups of mice in a range of commercially available cage sizes does not affect reproduction but behavioral measures suggest that the smallest cage tested, LP 18790, may be stressful for outbred mice when pups are present.
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Affiliation(s)
- Brianna N. Gaskill
- Purdue University Department of Comparative Pathobiology, West Lafayette, Indiana, United States of America
- Charles River, Wilmington, Massachusetts, United States of America
- * E-mail:
| | - Kathleen R. Pritchett-Corning
- Harvard University Faculty of Arts and Sciences, Office of Animal Resources, Cambridge, Massachusetts, United States of America
- Charles River, Wilmington, Massachusetts, United States of America
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9
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Newman AEM, Edmunds NB, Ferraro S, Heffell Q, Merritt GM, Pakkala JJ, Schilling CR, Schorno S. Using ecology to inform physiology studies: implications of high population density in the laboratory. Am J Physiol Regul Integr Comp Physiol 2015; 308:R449-54. [PMID: 25589015 DOI: 10.1152/ajpregu.00328.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Conspecific density is widely recognized as an important ecological factor across the animal kingdom; however, the physiological impacts are less thoroughly described. In fact, population density is rarely mentioned as a factor in physiological studies on captive animals and, when it is infrequently addressed, the animals used are reared and housed at densities far above those in nature, making the translation of results from the laboratory to natural systems difficult. We survey the literature to highlight this important ecophysiological gap and bring attention to the possibility that conspecific density prior to experimentation may be a critical factor influencing results. Across three taxa: mammals, birds, and fish, we present evidence from ecology that density influences glucocorticoid levels, immune function, and body condition with the intention of stimulating discussion and increasing consideration of population density in physiology studies. We conclude with several directives to improve the applicability of insights gained in the laboratory to organisms in the natural environment.
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Affiliation(s)
- Amy E M Newman
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Nicholas B Edmunds
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Shannon Ferraro
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Quentin Heffell
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Gillian M Merritt
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Jesse J Pakkala
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Cory R Schilling
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Sarah Schorno
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
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10
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Han Q, Zhang M, Guo C, Shen G, Wang Y, Li B, Xu Z. Effect of population density on reproduction in Microtus fortis under laboratory conditions. ACTA BIOLOGICA HUNGARICA 2014; 65:121-31. [PMID: 24873906 DOI: 10.1556/abiol.65.2014.2.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Between December 2011 and March 2012, the reproductive characteristics of Microtus fortis reared in the laboratory at different population densities were assessed. In all, 258 male and female voles were randomly divided into 4 groups and reared at densities of 2, 4, 6, and 8 animals per cage (sex ratio: 1:1). The results showed that the pregnancy rate (χ2 = 21.671, df = 3, P < 0.001) and first farrowing interval (F = 12.355, df = 3, P < 0.001) were significantly different among the different population density groups, but the mean litter size (mean ± SD) was not (F = 2.669, df = 3, P > 0.05). In particular, the reproductive index and sex hormone levels showed a significant difference among the different density groups studied.
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Affiliation(s)
- Qunhua Han
- Chinese Academy of Sciences Dongting Lake Station for Wetland Ecosystem Research, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture Changsha 410125 China Sichuan University College of Life Science Chendu 610064 China
| | - Meiwen Zhang
- Chinese Academy of Sciences Dongting Lake Station for Wetland Ecosystem Research, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture Changsha 410125 China
| | - Cong Guo
- Sichuan University College of Life Science Chendu 610064 China
| | - Guo Shen
- Chinese Academy of Sciences Dongting Lake Station for Wetland Ecosystem Research, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture Changsha 410125 China
| | - Yong Wang
- Chinese Academy of Sciences Dongting Lake Station for Wetland Ecosystem Research, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture Changsha 410125 China
| | - Bo Li
- Chinese Academy of Sciences Dongting Lake Station for Wetland Ecosystem Research, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture Changsha 410125 China
| | - Zhenggang Xu
- Chinese Academy of Sciences Dongting Lake Station for Wetland Ecosystem Research, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture Changsha 410125 China
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11
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Hemsworth PH, Rice M, Nash J, Giri K, Butler KL, Tilbrook AJ, Morrison RS. Effects of group size and floor space allowance on grouped sows: Aggression, stress, skin injuries, and reproductive performance1. J Anim Sci 2013; 91:4953-64. [DOI: 10.2527/jas.2012-5807] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- P. H. Hemsworth
- Animal Welfare Science Centre, Melbourne School of Land and Environment, University of Melbourne, Parkville, VIC 3010, Australia
| | - M. Rice
- Animal Welfare Science Centre, Melbourne School of Land and Environment, University of Melbourne, Parkville, VIC 3010, Australia
| | - J. Nash
- Animal Welfare Science Centre, Melbourne School of Land and Environment, University of Melbourne, Parkville, VIC 3010, Australia
| | - K. Giri
- Animal Welfare Science Centre, Department of Primary Industries, 600 Sneydes Road, Werribee, VIC 3030, Australia
| | - K. L. Butler
- Animal Welfare Science Centre, Department of Primary Industries, 600 Sneydes Road, Werribee, VIC 3030, Australia
| | - A. J. Tilbrook
- Animal Welfare Science Centre, Department of Physiology, Monash University, Clayton, VIC 3800 Australia
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Maurin AC, Chaveroux C, Lambert-Langlais S, Carraro V, Jousse C, Bruhat A, Averous J, Parry L, Ron D, Alliot J, Fafournoux P. The amino acid sensor GCN2 biases macronutrient selection during aging. Eur J Nutr 2012; 51:119-26. [PMID: 21614613 DOI: 10.1007/s00394-011-0205-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 05/09/2011] [Indexed: 10/18/2022]
Abstract
PURPOSE Selection of a balanced diet has a determinant impact on human health. Individual food preferences involve socio-cultural as well as physiological factors and evolve during aging. In mammals, physiological mechanisms governing food choices appear to require the sensing of nutrient concentrations in diet. This is particularly the case for dietary amino acids that are sensed by the protein kinase GCN2. It has been reported that GCN2 is involved in the adaptive response to amino acid imbalanced diets at the level of food intake and lipid metabolism. Here, we hypothesized that GCN2 may play a role in macronutrient selection and its age-related changes. METHODS Two groups of wild-type and GCN2 knock-out mice were subjected to a food self-selection protocol at ages 6, 12, 18 and 24 months. During each test, mice were allowed to create their own diets by selecting between three separate food sources, each containing either protein, fat or carbohydrates. RESULTS Our results show that the absence of GCN2 had two main age-related effects. First, it exacerbated fat preference at the expense of carbohydrate consumption. Second, it prevented the increase in protein intake. CONCLUSION These findings indicate that, in omnivores, the GCN2 ancient pathway participates in the control of food preference.
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Affiliation(s)
- Anne-Catherine Maurin
- Unité Mixte de Recherche 1019, Unité de Nutrition Humaine, Institut National de la Recherche Agronomique, Centre de Clermont-Ferrand/Theix, 63122 Saint Genès Champanelle, France
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13
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Whittaker AL, Howarth GS, Hickman DL. Effects of space allocation and housing density on measures of wellbeing in laboratory mice: a review. Lab Anim 2012; 46:3-13. [DOI: 10.1258/la.2011.011049] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In the majority of countries where there are legislative requirements pertaining to the use of animals in research, figures are quoted for minimum cage sizes or space allocation to be provided per animal. These figures are generally based on professional judgement and are in common usage. However, there is a growing trend and expectation that welfare science should inform regulatory decision-making. Given the importance of the potential welfare influences of cage size on the animals themselves, this paper presents the latest scientific knowledge on this topic in one of the most commonly used animals in research, the mouse. A comprehensive review of studies in laboratory mice was undertaken, examining the effects of space allocation per animal and animal density on established welfare indicators. To date, animal density studies have predominated, and the effects of space allocation per se are still relatively unclear. This information will guide those involved in facility management or legislative review, and provide a more solid foundation for further studies into the effects of routine husbandry practices on animal welfare.
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Affiliation(s)
- A L Whittaker
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, SA 5371, Australia
| | - G S Howarth
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, SA 5371, Australia
- Department of Gastroenterology, Women's and Children's Hospital, North Adelaide, SA 5006, Australia
| | - D L Hickman
- School of Medicine, Indiana University, Indianapolis, IN 46202, USA
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14
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Nistiar F, Racz O, Lukacinova A, Hubkova B, Novakova J, Lovasova E, Sedlakova E. Age dependency on some physiological and biochemical parameters of male Wistar rats in controlled environment. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2012; 47:1224-1233. [PMID: 22540644 DOI: 10.1080/10934529.2012.672071] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim of the study was to assess the age dependence on some physiological and serum chemistry parameters of male Wistar rats for the estimation of reference values in controlled environment. We are presenting values obtained from a large number of animals such as survival, average life span, body mass, food and water intake, serum chemistry parameters as total protein, albumin, transferrin and ferritin in serum. One part of this work compares the relationship between rat and human age. The maximal life span of our rats was determined to be about 4.4 years. The average life span was 3.75 years. The body weight quickly rose to the 85th week of life and then remained in the range of about 640-660 g up to the 163rd week when it began to decline. Food intake rose from the beginning to the maximum of about 39 g in the 33rd week and then decreased to about 20 g in the 163rd week. The water intake had a similar dynamics (about 43 mL in the 33rd week and 33 mL in the 163rd week). Levels of total protein in serum increased with age, in contrast, albumin levels decreased. Transferrin and ferritin decreased to approximately the 160th week of life and then increased.
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Affiliation(s)
- Frantisek Nistiar
- Department of Pathological Physiology, Faculty of Medicine, Safarik University, Kosice, Slovak Republic.
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15
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Dama MS, Singh NMP, Rajender S. High fat diet prevents over-crowding induced decrease of sex ratio in mice. PLoS One 2011; 6:e16296. [PMID: 21283594 PMCID: PMC3026815 DOI: 10.1371/journal.pone.0016296] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 12/20/2010] [Indexed: 12/02/2022] Open
Abstract
Adaptive theory predicts that mothers would be advantaged by adjusting the sex ratio of their offspring in relation to their offspring's future reproductive success. In the present study, we tested the effect of housing mice under crowded condition on the sex ratio and whether the fat content of the diet has any influence on the outcome of pregnancies. Three-week-old mice were placed on the control diet (NFD) for 3 weeks. Thereafter the mice were allotted randomly to two groups of 7 cages each with 4, 6, 8, 10, 12, 14, and 16 mice in every cage to create increasing crowding gradient and fed either NFD or high fat diet (HFD). After 4 weeks, dams were bred and outcomes of pregnancy were analyzed. The average dam body weight (DBW) at conception, litter size (LS) and SR were significantly higher in HFD fed dams. Further, male biased litters declined with increasing crowding in NFD group but not in HFD. The LS and SR in NFD declined significantly with increasing crowding, whereas only LS was reduced in HFD group. We conclude that female mice housed under overcrowding conditions shift offspring SR in favor of daughters in consistent with the TW hypothesis and high fat diet reduces this influence of overcrowding.
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Affiliation(s)
- Madhukar Shivajirao Dama
- Division of Endocrinology, Central Drug Research Institute (Council of Scientific and Industrial Research), Lucknow, India
| | - Negi Mahendra Pal Singh
- Biometry and Statistics Division, Central Drug Research Institute (Council of Scientific and Industrial Research), Lucknow, India
| | - Singh Rajender
- Division of Endocrinology, Central Drug Research Institute (Council of Scientific and Industrial Research), Lucknow, India
- * E-mail:
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Gelling M, Montes I, Moorhouse TP, Macdonald DW. Captive housing during water vole (Arvicola terrestris) reintroduction: does short-term social stress impact on animal welfare? PLoS One 2010; 5:e9791. [PMID: 20352093 PMCID: PMC2844416 DOI: 10.1371/journal.pone.0009791] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Accepted: 02/19/2010] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Animals captive bred for reintroduction are often housed under conditions which are not representative of their preferred social structure for at least part of the reintroduction process. Specifically, this is most likely to occur during the final stages of the release programme, whilst being housed during transportation to the release site. The degree of social stress experienced by individuals during this time may negatively impact upon their immunocompetence. METHODOLOGY/PRINCIPAL FINDINGS We examined two measure of stress--body weight and Leukocyte Coping Capacity (LCC)--to investigate the effects of group size upon captive-bred water voles destined for release within a reintroduction program. Water voles were housed in laboratory cages containing between one and eight individuals. LCC scores were negatively correlated with group size, suggesting that individuals in larger groups experienced a larger degree of immuno-suppression than did individuals housed in smaller groups or individually. During the course of the study mean body weights increased, in contrast to expectations from a previous study. This was attributed to the individuals sampled being sub-adults and thus growing in length and weight during the course of the investigation. CONCLUSIONS/SIGNIFICANCE The reintroduction process will inevitably cause some stress to the release cohort. However, for water voles we conclude that the stress experienced may be reduced by decreasing group size within captive colony and/or transportation housing practises. These findings are of significance to other species' reintroductions, in highlighting the need to consider life-history strategies when choosing housing systems for animals being maintained in captivity prior to release to the wild. A reduction in stress experienced at the pre-release stage may improve immunocompetence and thus animal welfare and initial survival post-release.
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Affiliation(s)
- Merryl Gelling
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Oxford, United Kingdom.
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Foltz C, Carbone L, DeLong D, Rollin BE, Van Loo P, Whitaker J, Wolff A. Considerations for determining optimal mouse caging density. Lab Anim (NY) 2008; 36:40-9. [PMID: 17957179 DOI: 10.1038/laban1107-40] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Accepted: 09/14/2007] [Indexed: 11/09/2022]
Abstract
At the 2006 National Meeting of the American Association of Laboratory Animal Science, a panel discussed the question of what constitutes optimal or acceptable housing density for mice. Though there is a consensus that present guidelines are somewhat arbitrarily defined, scientific research has not yet been able to provide clear recommendations for amending them. Speakers explored the many factors that influence decisions on mouse housing, including regulatory requirements, scientific data and their interpretation, financial considerations and ethical concerns. The panel largely agreed that animal well-being should be the measure of interest in evaluating housing density and that well-being includes not only physical health, but also animals' behavior, productivity and preference.
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Affiliation(s)
- Charmaine Foltz
- Division of Veterinary Resources, National Institutes of Health, Bethesda, MD, USA
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18
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Olsson IAS, Westlund K. More than numbers matter: The effect of social factors on behaviour and welfare of laboratory rodents and non-human primates. Appl Anim Behav Sci 2007. [DOI: 10.1016/j.applanim.2006.05.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yildiz A, Hayirli A, Okumus Z, Kaynar O, Kisa F. Physiological profile of juvenile rats: effects of cage size and cage density. Lab Anim (NY) 2007; 36:28-38. [PMID: 17245386 DOI: 10.1038/laban0207-28] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Accepted: 06/12/2006] [Indexed: 11/09/2022]
Abstract
Although there is a general consensus that housing conditions affect the well-being of laboratory animals, the ideal cage size and density for housing laboratory rodents has not been established. The authors investigated the effects of cage size and cage density on growth, organ development, metabolic profile, and hemogram in juvenile Sprague-Dawley rats. Larger cages and increased cage density were associated with depressions in body weight and in the weights of several organs. In general, increasing group size and density correlated more strongly with detrimental effects on the growth of females than males, although hemogram values indicated that males are more prone to emotional stress and immune suppression than females in response to increasing group size and crowding.
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Affiliation(s)
- Ahmet Yildiz
- Department of Animal Husbandry, Faculty of Veterinary Medicine, Atatürk University, Erzurum, 25700, Turkey
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20
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The effects of individual housing on mice and rats: a review. Anim Welf 2006. [DOI: 10.1017/s0962728600030669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
AbstractIsolating an animal refers to the situation where the animal is physically fully demarcated from conspecifics without physical, visual, olfactory and auditory contact. Animals housed in separate cages in the same room are, although deprived of physical and visual contact, still in olfactory and auditory contact, and thus not totally isolated. During the fifties and sixties several studies claimed to show physiological and behavioural differences between individually and group housed rats and mice. The so-called ‘Isolation Syndrome’ characterised by changes in corticosterone levels, metabolism, growth, and behaviour was introduced, rather as a model for psychoneurosis than through any concern for animal welfare. Today, it is often stated as common knowledge in laboratory animal science textbooks that individual housing as well as isolation of rats and mice has an effect on physiology and behaviour. It is, however, unclear whether this effect actually impairs animal welfare.The aim of this paper is to analyse studies on individual housing of mice and rats to evaluate whether there is documented proof that individual housing affects welfare, and, alternatively whether it is possible to house these animals individually without negative impact on welfare, eg by providing special housing improvements.A range of studies have shown that individual housing or isolation has effects on corticosterone, the open field behaviour, barbiturate sleeping time and the metabolism of different pharmaceuticals in the animals. However, this review of 37 studies in rats and 17 studies in mice showed divergence in test results difficult to explain, as many studies lacked basal information about the study, eg information on genetic strains and housing conditions, such as bedding, enrichment and cage sizes. Furthermore, test and control groups most frequently differed in cage sizes and stocking densities, and behavioural tests differed in ways which may very well explain the differences in results. Overall, there seemed to be an effect of individual housing, although it may be small, and it seems reasonable to assume that, through making small changes in the procedures and housing environments, the effects can be minimised or even eliminated. More well-controlled and standardised studies are needed to give more specific answers to the questions this issue poses.
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21
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Scott ME. High transmission rates restore expression of genetically determined susceptibility of mice to nematode infections. Parasitology 2006; 132:669-79. [PMID: 16393368 DOI: 10.1017/s0031182005009583] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2005] [Revised: 10/26/2005] [Accepted: 10/26/2005] [Indexed: 11/06/2022]
Abstract
This study investigated why the susceptible or resistance phenotype to the nematode Heligmosomoides polygyrus was lost when susceptible (C57BL/6) and resistant (Balb/c) strains of mice were housed together in indoor arenas with continuous transmission of the parasite larvae present in peat trays (Scott, 1991). First, both strains expressed their normal phenotype when given a controlled challenge while living in arenas, and when experimentally infected with only 5 parasite larvae. To test whether chronic exposure to peat altered the resistance phenotype, mice were given a challenge infection while living on peat. C57BL/6 mice living on peat had higher egg production and higher worm numbers than Balb/c mice, except at 2 months post-challenge. Finally, natural transmission rates were increased in arena experiments through either regular replacement of arena mice with naïve mice or direct introduction of additional larvae. A transient difference in infection levels between strains was detected in response to a modest increase in transmission whereas a 10-fold increase in transmission allowed C57BL/6 mice to exhibit the typical profile of high egg production and elevated worm numbers. These data indicate that C57BL/6 mice are less able to regulate parasite numbers at high transmission rates compared with lower transmission rates.
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Affiliation(s)
- M E Scott
- Institute of Parasitology, Macdonald Campus of McGill University, 21 111 Lakeshore Road, Ste-Anne de Bellevue, Quebec, Canada H9X 3V9.
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Vissers K, De Jongh R, Hoffmann V, Heylen R, Crul B, Meert T. Internal and External Factors Affecting the Development of Neuropathic Pain in Rodents. Is It All About Pain? Pain Pract 2003; 3:326-42. [PMID: 17166129 DOI: 10.1111/j.1530-7085.2003.03037.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
It is important to know the factors that will influence animal models of neuropathic pain. A good reproducibility and predictability in different strains of animals for a given test increases the clinical relevance and possible targeting. An obligatory requirement for enabling comparisons of results of different origin is a meticulous definition of the specific sensitivities of a model for neuropathic pain and a description of the test conditions. Factors influencing neuropathic pain behavior can be subdivided in external and internal factors. The most important external factors are; timing of the measurement of pain after induction of neuropathy, circadian rhythms, seasonal influences, air humidity, influence of order of testing, diet, social variables, housing and manipulation, cage density, sexual activity, external stress factors, and influences of the experimenter. The internal factors are related to the type of animal, its genetic background, gender, age, and the presence of homeostatic adaptation mechanisms to specific situations or stress. In practice, the behavioral presentations to pain depend on the combination of genetic and environmental factors such as accepted social behavior. It also depends on the use of genetic manipulation of the animals such as in transgenic animals. These make the interpretation of data even more difficult. Differences of pain behavior between in- and outbred animals will be better understood by using modern analysis techniques. Substrains of animals with a high likelihood for developing neuropathic pain make the unraveling of specific pathophysiological mechanisms possible. Concerning the effect of stress on pain, it is important to differentiate between external and internal stress such as social coping behavior. The individual dealing with this stress is species sensitive, and depends on the genotype and the social learning. In the future, histo-immunological and genetic analysis will highlight similarities of the different pathophysiological mechanisms of pain between different species and human subjects. The final objective for the study of pain is to describe the genetics of the eliciting pain mechanisms in humans and to look for correlations with the knowledge from basic research. Therefore, it is necessary to know the genetic evolution of the different mechanisms in chronic pain. In order to be able to control the clinical predictability of a putative treatment the evolutionary pharmacogenomic structure of specific transmitters and receptors must be clarified.
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Affiliation(s)
- K Vissers
- Multidisciplinary Pain Center, Ziekenhuis Oost-Limburg, Genk, Belgium.
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Chesler EJ, Wilson SG, Lariviere WR, Rodriguez-Zas SL, Mogil JS. Identification and ranking of genetic and laboratory environment factors influencing a behavioral trait, thermal nociception, via computational analysis of a large data archive. Neurosci Biobehav Rev 2002; 26:907-23. [PMID: 12667496 DOI: 10.1016/s0149-7634(02)00103-3] [Citation(s) in RCA: 247] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Laboratory conditions in biobehavioral experiments are commonly assumed to be 'controlled', having little impact on the outcome. However, recent studies have illustrated that the laboratory environment has a robust effect on behavioral traits. Given that environmental factors can interact with trait-relevant genes, some have questioned the reliability and generalizability of behavior genetic research designed to identify those genes. This problem might be alleviated by the identification of the most relevant environmental factors, but the task is hindered by the large number of factors that typically vary between and within laboratories. We used a computational approach to retrospectively identify and rank sources of variability in nociceptive responses as they occurred in a typical research laboratory over several years. A machine-learning algorithm was applied to an archival data set of 8034 independent observations of baseline thermal nociceptive sensitivity. This analysis revealed that a factor even more important than mouse genotype was the experimenter performing the test, and that nociception can be affected by many additional laboratory factors including season/humidity, cage density, time of day, sex and within-cage order of testing. The results were confirmed by linear modeling in a subset of the data, and in confirmatory experiments, in which we were able to partition the variance of this complex trait among genetic (27%), environmental (42%) and genetic x environmental (18%) sources.
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Affiliation(s)
- Elissa J Chesler
- Department of Psychology, University of Illinois at Urbana-Champaign, 61820, USA
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24
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Abstract
Housing conditions affect behavioral and biological responses of animals. We investigated the effect of same-sex-grouped (G), crowded (GC) and isolated (I) conditions on the growth of B16 melanoma or Meth A fibrosarcoma implanted in the footpad of syngeneic male C57BL / 6 or BALB / c mice. Differential housing altered host resistance to tumor growth. The host responses to stress were reflected in thymic atrophy, which was lowest in the G mice, highest in the GC mice and intermediate in the I mice. The GC condition was a more stressful social environment than the I condition in both male C57BL / 6 and BALB / c mice. Reflecting the extent of psychosocial stress, tumor growth was augmented in the order of GC, I and G condition, and a negative mass correlation between tumor and thymus was observed, thus clearly indicating that the host resistance to tumors was attenuated by psychosocial stress. Furthermore, the stress-enhanced tumor growth and thymus atrophy were completely abrogated by the oral administration of the non-selective beta-adrenergic antagonist, propranolol. On the contrary, the chronic administration of corticosterone significantly induced the atrophy of thymus and spleen without affecting tumor growth. These results suggest an interrelationship among psychosocial stress, tumor growth and beta-adrenergic activation.
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Affiliation(s)
- Hideo Hasegawa
- Itto Institute of Life Science Research, Happy World, Inc., Fuchu, Tokyo 183-0011, Japan
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25
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Abstract
Estrogen has effects on activity levels and emotional reactivity in both humans and rats. In a recent study conducted in ovariectomized (OVX) C57BL/6 (C57) mice we found that treatment with estradiol benzoate (EB) increased anxiety, fear learning, and running wheel activity relative to vehicle control (Veh). The present study was conducted to examine the stability of these findings across mouse strains (C57 and Swiss-Webster; SW), to get a better sense of the magnitude of the anxiety response by reducing baseline anxiety levels, and to discover if EB affects activity levels in a safe environment other than the home-cage running wheel. Mice of both strains treated with EB (s.c. implant, 25 microg in sesame oil, which enters the body over 5 weeks) were more anxious than Veh animals in the open field, elevated plus, and dark-light transition tests. SW animals were less anxious than C57 in the elevated plus. EB-treated animals of both strains were more active in the running wheel than Veh animals, and more active in the test of spontaneous activity in the home cage. EB-treatment also increased fear learning in a step-down avoidance task. EB appears to have a consistent but moderate effect in elevating anxiety and in increasing fear learning in two strains of mice. It is also involved in increasing activity in two different types of locomotion in the safer home cage. We conclude that these results of increased anxiety/fear and increased activity are suggestive of a general increase in arousal, with both sets of responses increasing the likelihood of reproductive behaviors occurring only when the environment predicts success.
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Affiliation(s)
- M A Morgan
- Laboratory of Neurobiology and Behavior, The Rockefeller University, 1230 York Avenue, Box 275, New York, NY 10021, USA
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Caplea A, Seachrist D, Dunphy G, Ely D. Sodium-induced rise in blood pressure is suppressed by androgen receptor blockade. Am J Physiol Heart Circ Physiol 2001; 280:H1793-801. [PMID: 11247793 DOI: 10.1152/ajpheart.2001.280.4.h1793] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our objective was to test the hypothesis that 1) a high Na (HNa, 3%) diet would increase blood pressure (BP) in male Wistar-Kyoto (WKY) and spontaneously hypertensive Y chromosome (SHR/y) rat strains in a territorial colony; 2) sympathetic nervous system (SNS) blockade using clonidine would lower BP on a HNa diet; and 3) prepubertal androgen receptor blockade with flutamide would lower BP on a HNa diet. A 2 x 4 factorial design used rat strains (WKY, SHR/y) and treatment [0.3% normal Na (NNa), 3% HNa, HNa/clonidine, and HNa/flutamide]. BP increased in both strains on the HNa diet (P < 0.0001). There was no significant decrease in BP in either strain with clonidine treatment. Androgen receptor blockade with flutamide significantly decreased BP in both strains (P < 0.0001) and normalized BP in the SHR/y colony. Neither heart rate nor activity could explain these BP differences. In conclusion, a Na sensitivity was observed in both strains, which was reduced to normotensive values by androgen blockade but not by SNS blockade.
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Affiliation(s)
- A Caplea
- Department of Biology, The University of Akron, Akron, Ohio 44325-3908, USA.
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Caplea A, Seachrist D, Dunphy G, Ely D. SHR Y chromosome enhances the nocturnal blood pressure in socially interacting rats. Am J Physiol Heart Circ Physiol 2000; 279:H58-66. [PMID: 10899041 DOI: 10.1152/ajpheart.2000.279.1.h58] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our objective was to test the hypothesis that nocturnal mean arterial pressure (MAP), heart rate (HR), and activity would be increased in 1) colony over individually caged rats and 2) the spontaneously hypertensive rat (SHR) Y chromosome strain (SHR/y colony) compared with Wistar-Kyoto (WKY) rats. MAP, HR, and activity were monitored using radiotelemetry. The nocturnal MAP rise expressed as the percentage change in MAP from light to dark was increased (P < 0.05) in the SHR/y colony. The SHR Y chromosome increased MAP in both the colony and caged groups compared with WKY (P < 0.001). The SHR/y colony animals spent 23% of a 24-h period at a MAP >120 mmHg, whereas the WKY colony animals spent 2% of a 24-h period in this range. The MAP of the SHR/y colony on clonidine was reduced (P < 0.001) to WKY baseline values. Activity but not HR was increased (P < 0.01) in the WKY and SHR/y colonies compared with caged animals. In conclusion, colony housing and the SHR Y chromosome increased MAP compared with individually caged housing.
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Affiliation(s)
- A Caplea
- Department of Biology, The University of Akron, Akron, Ohio 44325-3908, USA.
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28
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Strange KS, Kerr LR, Andrews HN, Emerman JT, Weinberg J. Psychosocial stressors and mammary tumor growth: an animal model. Neurotoxicol Teratol 2000; 22:89-102. [PMID: 10642118 DOI: 10.1016/s0892-0362(99)00049-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stressful life events and the ability to cope with stress may play a role in the progression of breast cancer; however, the complex relationship between stressors and tumor growth is difficult to investigate in humans. Our studies have utilized the androgen-responsive Shionogi mouse mammary carcinoma (AR SC115) in male mice to investigate the effects of social housing condition on tumor growth rates and responses to chemotherapy. We demonstrate that, depending on social housing condition, mammary tumor growth and response to chemotherapy can both increase and decrease. We have examined the possible role(s) of 1) psychosocial variables, 2) testosterone and corticosterone, hormones altered by stress and known to stimulate SC115 cells in vivo and in vitro, 3) NK cells, one of the body's first lines of defense against tumor cells, 4) stress proteins, in mediating the differential tumor growth rates observed in our model. This review discusses the investigations we have undertaken to elucidate the mechanisms through which a psychosocial stressor, social housing condition, can alter tumor growth rate.
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Affiliation(s)
- K S Strange
- Department of Anatomy, University of British Columbia, Vancouver, Canada
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Haller J, Fuchs E, Halász J, Makara GB. Defeat is a major stressor in males while social instability is stressful mainly in females: towards the development of a social stress model in female rats. Brain Res Bull 1999; 50:33-9. [PMID: 10507469 DOI: 10.1016/s0361-9230(99)00087-8] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Social stress models appear useful in elucidating the interrelationship between stress, mood disorders, and drug efficacy. However, reliable social stress models for females are virtually lacking. The aim of this study was to determine stress-related consequences of (a) defeat in aggressive encounters and (b) social instability, in male and female rats. Defeat in male and female subjects was induced by aggressive male residents and female residents made aggressive by surgery (mediobasal hypothalamic lesion [MBHL]), respectively. Aggressiveness of resident males and resident MBHL females was remarkably similar. Alternating isolation and mixed-sex crowding phases with membership rotation were used to induce social instability. Aggression was kept low in the latter paradigm by manipulating crowding group composition. Defeat stress reduced weight gain, and increased both adrenals and plasma corticosterone in males. Only adrenal weight was affected in females. Social instability reduced weight gain, and induced thymus involution, adrenal hypertrophy and elevated plasma corticosterone levels in females. Only weight gain and thymus weights were affected in males. It is concluded that defeat stresses males more than females, while social instability is more stressful for females than for males, if aggressive contacts are low. It is suggested that the social instability model is a good model of social stress in females.
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Affiliation(s)
- J Haller
- Institute of Experimental Medicine, Budapest, Hungary.
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30
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Fullwood S, Hicks TA, Brown JC, Norman RL, McGlone JJ. Floor Space Needs for Laboratory Mice: C56BL/6 Males in Solid-bottom Cages with Bedding. ILAR J 1998; 39:29-36. [PMID: 11406686 DOI: 10.1093/ilar.39.1.29] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Measures of performance, mortality, adrenal weights, plasma glucocorticoid concentration, and selected immune measures were collected in an attempt to define space needs of laboratory mice. Six replications of 3 C57BL/6 male mice per cage were examined while housed on bedding at 5, 10, 15, or 20 in(2) (32.2, 64.5, 96.8, or 129 cm(2)) per mouse. Body weights were not influenced by treatment; however, mice in smaller spaces (5 in(2) per mouse) consumed or wasted more feed and water than mice given greater space allowances. Mice given the least amount of space (5 in(2) per mouse) had greater lymphocyte proliferation in response to the T-cell mitogen PHA than mice given more space. Mice provided 10 in(2) per mouse had greater natural killer cytotoxicity than mice given greater or less space. Mouse mortality was greater as more space was provided. In contrast, adrenal weights and plasma glucocorticoid concentrations were progressively greater with lower space allowances. The National Research Council 1996 recommendation of 15 in(2) per mouse, for this strain and sex of mice, would result in greater mortality and reduced activity of some immune measures. Socially housed male C57BL/6 mice will benefit from less space than recommended by the National Research Council in 1996.
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Affiliation(s)
- Steven Fullwood
- Department of Animal Science, Texas Tech University, Lubbock, Texas, USA
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31
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Marcotte H, Lavoie MC. Oral microbial ecology and the role of salivary immunoglobulin A. Microbiol Mol Biol Rev 1998; 62:71-109. [PMID: 9529888 PMCID: PMC98907 DOI: 10.1128/mmbr.62.1.71-109.1998] [Citation(s) in RCA: 297] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In the oral cavity, indigenous bacteria are often associated with two major oral diseases, caries and periodontal diseases. These diseases seem to appear following an imbalance in the oral resident microbiota, leading to the emergence of potentially pathogenic bacteria. To define the process involved in caries and periodontal diseases, it is necessary to understand the ecology of the oral cavity and to identify the factors responsible for the transition of the oral microbiota from a commensal to a pathogenic relationship with the host. The regulatory forces influencing the oral ecosystem can be divided into three major categories: host related, microbe related, and external factors. Among host factors, secretory immunoglobulin A (SIgA) constitutes the main specific immune defense mechanism in saliva and may play an important role in the homeostasis of the oral microbiota. Naturally occurring SIgA antibodies that are reactive against a variety of indigenous bacteria are detectable in saliva. These antibodies may control the oral microbiota by reducing the adherence of bacteria to the oral mucosa and teeth. It is thought that protection against bacterial etiologic agents of caries and periodontal diseases could be conferred by the induction of SIgA antibodies via the stimulation of the mucosal immune system. However, elucidation of the role of the SIgA immune system in controlling the oral indigenous microbiota is a prerequisite for the development of effective vaccines against these diseases. The role of SIgA antibodies in the acquisition and the regulation of the indigenous microbiota is still controversial. Our review discusses the importance of SIgA among the multiple factors that control the oral microbiota. It describes the oral ecosystems, the principal factors that may control the oral microbiota, a basic knowledge of the secretory immune system, the biological functions of SIgA, and, finally, experiments related to the role of SIgA in oral microbial ecology.
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Affiliation(s)
- H Marcotte
- Département de Microbiologie-Immunologie, Faculté de Médecine, Université Laval, Québec, Canada
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Barnard CJ, Behnke JM, Gage AR, Brown H, Smithurst PR. Modulation of behaviour and testosterone concentration in immunodepressed male laboratory mice (Mus musculus). Physiol Behav 1997; 61:907-17. [PMID: 9177566 DOI: 10.1016/s0031-9384(97)00011-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Recent ideas suggest that current immunocompetence may act as a constraint on behavioural and physiological decisions, where these risk imposing an additional burden on immune function. We tested this in the context of time budgeting and the secretion of the potentially immunodepressive hormones testosterone and corticosterone, by treating adult male CFLP laboratory mice with antithymocyte serum (ATS) to depress thymus-mediated immune function. In comparison with males given a naive rabbit serum (NRS) vehicle control, ATS-treated mice showed a reduction in serum testosterone concentration, aggressive behaviour, and general activity, and maintained time spent sleeping, relative to pretreatment levels. Behaviours that differed between treatments correlated with measures of immunodepression (reduction in relative thymus weight or serum total IgG concentration), but relationships with behavioural changes were independent of those with testosterone. There was little evidence that changes were affected by social status. The results are discussed in the context of the adaptive modulation of immune function and physiological and behavioural decision-making.
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Affiliation(s)
- C J Barnard
- Department of Life Science, University of Nottingham, University Park, UK.
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Barnard CJ, Behnke JM, Sewell J. Environmental enrichment, immunocompetence, and resistance to Babesia microti in male mice. Physiol Behav 1996; 60:1223-31. [PMID: 8916175 DOI: 10.1016/s0031-9384(96)00174-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Groups of male CFLP mice housed in cages furnished with shelves and nestboxes showed increased aggression and reduced resistance to an experimental infection of Babesia microti when compared with groups in unfurnished cages. Both a bystander measure of immunocompetence (serum total IgG concentration) and resistance to B. microti decreased as the number of attacks received by mice increased, but increased with the number of times individuals were recorded on shelves or in nestboxes. Serum concentrations of testosterone and corticosterone were generally downregulated in furnished cages; the absence of hormone-related reduction in resistance may have been due partly to this, but partly also to the apparent modulation of hormone concentrations in relation to concurrent immunocompetence. Some welfare implications of the results are considered.
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Affiliation(s)
- C J Barnard
- Behaviour and Ecology Research Group, University of Nottingham, University Park, UK.
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Brown KJ, Grunberg NE. Effects of environmental conditions on food consumption in female and male rats. Physiol Behav 1996; 60:293-7. [PMID: 8804679 DOI: 10.1016/0031-9384(96)00020-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The present experiment examined food and water consumption under different housing conditions in 20 female and 20 male Wistar rats. Food and water consumption were measured for 6 h a day following an 18-h same-sex crowded or individual housing period for each of 6 days. All subjects were individually housed during the 6-h measurement period and had access to food and water. Female rats consumed more food and water than did male rats during the 6-h period, regardless of their 18-h housing condition. In addition, previously crowded rats consumed more food and water during the 6-h period than did rats that were previously individually housed. During the 18-h period, when subjects were differentially housed, males consumed more food and water than did females; crowded rats ate less than did individually housed rats; and crowded rats drank more water than did individually housed rats. Based on plasma corticosterone data, the female and male rats were differentially affected by housing conditions. The present results are discussed with regard to housing conditions per se and sex differences in stress responses to housing.
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Affiliation(s)
- K J Brown
- Department of Medical and Clinical Psychology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799, USA
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Lin AH, Castle CK, Melchior GW, Marotti KR. The effect of population density on the development of experimental atherosclerosis in female mice. Atherosclerosis 1995; 115:85-8. [PMID: 7669090 DOI: 10.1016/0021-9150(94)05502-a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effect of cage population density on plasma lipids and the development of atherosclerosis was examined in female C57BL/6 mice. Mice were housed at a density of one, two or five animals per cage and fed an atherogenic diet for 28 weeks. Subsequently, the animals were bled, sacrificed, the hearts removed and the extent of fatty lesion development in the aorta examined and quantified. As the population density increased, there was a statistically significant increase in total cholesterol levels, VLDL+LDL cholesterol levels, the VLDL+LDL/HDL ratio and lesion severity. These differences are due to the psychosocial stress associated with living within a confined space with high population density over an extended period of time.
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Affiliation(s)
- A H Lin
- Upjohn Laboratories, Kalamazoo, MI, USA
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Barnard CJ, Behnke JM, Sewell J. Social behaviour and susceptibility to infection in house mice (Mus musculus): effects of group size, aggressive behaviour and status-related hormonal responses prior to infection on resistance to Babesia microti. Parasitology 1994; 108 ( Pt 5):487-96. [PMID: 8052503 DOI: 10.1017/s0031182000077349] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Associations between social rank, immunodepression and resistance to Babesia microti infection within single-sex groups of male house mice suggest rank-dependent suites of response involving different hormonal and immune changes in relation to aggressive behaviour and group size prior to infection. Reduced resistance among high-ranking males was associated with increased serum testosterone and corticosterone concentration and reduced serum immunoglobulin, but was independent of group size. Among low-ranking males, hormonal changes were not associated with resistance to B. microti but changes in corticosterone concentration and measures of immunodepression increased with group size and aggressive behaviour. The results concur with earlier findings suggesting differences between high- and low-ranking mice in their physiological responses to social experience and consequently reduced resistance to B. microti infection among high-ranking individuals.
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Affiliation(s)
- C J Barnard
- Behaviour and Ecology Research Group, University of Nottingham, University Park, UK
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Barnard CJ, Behnke JM, Sewell J. Social behaviour, stress and susceptibility to infection in house mice (Mus musculus): effects of duration of grouping and aggressive behaviour prior to infection on susceptibility to Babesia microti. Parasitology 1993; 107 ( Pt 2):183-92. [PMID: 8414673 DOI: 10.1017/s0031182000067299] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Unrelated and initially unfamiliar male CFLP mice, maintained for different periods in groups of 6, differed in both their rate of clearance of Babesia microti and the time taken to reach peak parasitaemia in relation to their aggressive behaviour within groups prior to infection. Males maintained in groups for shorter periods and showing more aggression within their group were slower to clear infection and males showing more marked external evidence of aggressive interaction reached a peak of parasitaemia sooner. Serum IgG and corticosterone analyses were consistent with increased aggression causing stress-induced immunodepression but relationships with aggression and social status were not simple. Males showing more aggression tended to enter their groups with higher levels of corticosterone and, to a lesser extent, reduced levels of IgG compared with other mice. The results thus suggest that increased susceptibility to disease may be a cost to males aggressively maintaining high social status.
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Affiliation(s)
- C J Barnard
- Department of Life Science, University of Nottingham, University Park
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Rowse GJ, Weinberg J, Bellward GD, Emerman JT. Endocrine mediation of psychosocial stressor effects on mouse mammary tumor growth. Cancer Lett 1992; 65:85-93. [PMID: 1511412 DOI: 10.1016/0304-3835(92)90217-j] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have demonstrated that differential housing alters the growth rate of the androgen-responsive Shionogi mouse mammary carcinoma (SC115). In the present study we wished to determine if changes in plasma levels of hormones or a shift in the responsiveness of the tumor cells to hormones was responsible for the differential tumor growth rates observed. Plasma testosterone and corticosterone levels were assayed 24 h, 3 days and 1 week post tumor cell/vehicle injection. Also 3 weeks post injection androgen and glucocorticoid receptor binding capacity (Bmax) and binding affinity (Kd) and the in vitro responsiveness of tumor cells to dihydrotestosterone and hydrocortisone were measured. At 24 h post injection, plasma testosterone levels were significantly increased in mice with large tumors, but remained low in mice with small tumors. Plasma corticosterone levels were significantly elevated in mice with small tumors compared to those of mice with large tumors at all time points measured. Androgen and glucocorticoid receptor binding capacity and binding affinity of tumor cells did not differ among groups. Further, all groups tested had the ability to respond to dihydrotestosterone and hydrocortisone in vitro. These data indicate that an effect of housing condition on plasma levels of steroid hormones may, in part, mediate the differential tumor growth rates observed in this model.
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MESH Headings
- Analysis of Variance
- Animals
- Cell Division/drug effects
- Corticosterone/blood
- Dihydrotestosterone/pharmacology
- Hydrocortisone/pharmacology
- Male
- Mammary Neoplasms, Experimental/blood
- Mammary Neoplasms, Experimental/metabolism
- Mammary Neoplasms, Experimental/pathology
- Mice
- Mice, Inbred Strains
- Neoplasms, Hormone-Dependent/metabolism
- Neoplasms, Hormone-Dependent/pathology
- Receptors, Androgen/metabolism
- Receptors, Glucocorticoid/metabolism
- Stress, Psychological/physiopathology
- Testosterone/blood
- Tumor Cells, Cultured
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Affiliation(s)
- G J Rowse
- Department of Anatomy, University of British Columbia, Vancouver, Canada
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