DISSERTATION RESEARCH: The influence of parasite load on glucocorticoid hormone levels: An experimental assessment in a natural setting

论文研究：寄生虫负荷对糖皮质激素水平的影响：自然环境中的实验评估

• 批准号: 0806707
• 负责人: Matthew Gompper
• 金额: $ 1.15万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0806707&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; influence; parasite; load

Stress hormones (glucocorticoids) are of great interest to ecologists because they impact animal fitness and survival and provide a direct, quantifiable index of sublethal stress. Baseline glucocorticoid levels are known to be correlated with age, sex, and social rank of vertebrates. However, few causal relationships have been established between glucocorticoid levels and factors intrinsic to free-ranging animals and their environment. Interactions between stress hormones and parasites are predicted to exist because glucocorticoids can enhance or depress the immune system. This study will determine the nature of the relationship between macroparasites and stress, using glucocorticoid levels as an indicator of stress, in a common, free-ranging mammal. Objectives of this research are to quantify baseline fecal glucocorticoid levels and correlate those with animal characteristics (e.g., age, sex) and parasite burden, experimentally reduce ectoparasites and helminths to test causal relationships between glucocorticoid levels and parasite burden, and determine if glucocorticoid levels of parasite-reduced individuals influence subsequent parasite acquisition. Glucocorticoid concentrations in animals are increasingly being used to evaluate wildlife health, responses to their environment, and influence management decisions. For such decisions to be most effective it is imperative that we identify factors important to baseline stress values. This study will determine the influence of common parasites on the endocrine system and if baseline glucocorticoid levels predispose individuals to infection. Evaluating such interactions in an experimental context will enhance our ability to understand animal stress and make informed management decisions when disease and stress are issues of concern. Broader impacts include the training and education of students. All elements of this project will be incorporated into a wildlife disease ecology course for undergraduates. Students will participate in experiential learning exercises that involve them in all aspects of the project during lab and field sessions.

应激激素（糖皮质激素）是生态学家非常感兴趣的，因为它们影响动物的适应性和生存，并提供直接的、可量化的亚致死应激指标。已知糖皮质激素的基线水平与脊椎动物的年龄、性别和社会地位有关。然而，糖皮质激素水平与自由放养动物及其环境固有因素之间的因果关系很少。由于糖皮质激素可以增强或抑制免疫系统，预计应激激素和寄生虫之间的相互作用是存在的。这项研究将利用糖皮质激素水平作为一种常见的、自由放养的哺乳动物的压力指标，确定大型寄生虫与压力之间关系的本质。本研究的目的是量化粪便糖皮质激素的基线水平，并将其与动物特征（如年龄、性别）和寄生虫负担联系起来，实验减少体外寄生虫和蠕虫，以测试糖皮质激素水平与寄生虫负担之间的因果关系，并确定减少寄生虫个体的糖皮质激素水平是否影响随后的寄生虫获取。动物体内的糖皮质激素浓度越来越多地被用于评估野生动物的健康、对环境的反应以及影响管理决策。为了使这些决定最有效，我们必须确定对基线压力值重要的因素。本研究将确定常见寄生虫对内分泌系统的影响，以及基线糖皮质激素水平是否使个体易受感染。在实验环境中评估这种相互作用将提高我们理解动物压力的能力，并在疾病和压力成为关注的问题时做出明智的管理决策。更广泛的影响包括对学生的培训和教育。本项目的所有内容将被纳入本科生野生动物疾病生态学课程。学生将在实验室和实地学习期间参与体验式学习练习，涉及项目的各个方面。