HOUSING ENRICHMENT AND EXPERIMENTAL MANIPULATION

该项目的长期目标是利用最先进的方法，对住房丰富和普通饲养以及实验程序对大鼠正常心血管和内分泌生理的影响进行系统研究。预计结果将极大地帮助机构动物保护和利用委员会确定在啮齿动物住宅区可以或不可以进行哪些程序，以及丰富住房环境是否显著减轻啮齿动物的压力。具体目标是：(1)评估不同程度的居住环境对老鼠的伤害(或没有伤害)；(2)评估正在进行普通饲养或实验程序的动物，或“见证”对其他动物进行这些程序的动物的痛苦程度。这些研究将在3个月、6个月或12个月大的雄性和雌性大鼠身上进行，它们是从商业商贩那里获得的四个常用的近交系。动物将使用无线电遥测发射器持续监测动脉血压和心率，或使用慢性留置静脉导管连续采集血液样本，以确定血浆应激相关激素(儿茶酚胺、皮质酮和催乳素)的水平。还将监测其他变量(体重增加、食物和水的消耗以及发情周期)，以衡量大鼠的生理状态。待评估的住房条件包括：隔离(单人)住房、成对(双人)住房、带有“咀嚼”和“攀爬/躲藏”“玩具”的隔离住房，以及每天可短暂接触非常丰富的环境的隔离住房。还将评估对环境住房条件的适应情况。动物将接触到或目睹其他动物被做的常见饲养和实验操作将包括：移到新笼子、手束缚和S.C.注射，用尾静脉注射，放在啮齿动物抑制架上一小段时间，目睹其他动物被斩首，并见证从其他动物身上采集组织。虽然这个项目是描述性的，不是假设驱动的，但它应该提供非常实际和重要的结果，供当地IACUC审查动物规程时使用，并可供PHS、AAALAC、ILAR和USDA等国家组织在发布这一领域的要求、指南和法规时使用。

The long-range goal of this project is to conduct systematic studies on the effects of housing enrichment and common husbandry and experimental procedures on the normal cardiovascular and endocrine physiology of rats using state-of-the-art methodologies. It is anticipated that the results will greatly assist Institutional Animal Care and Use Committees in their determination of what procedures can or cannot be conducted in rodent housing areas and whether or not enrichment of the housing environment significantly reduces stress in rodents. The specific aims are: (1) To evaluate several levels of enrichment of the housing environment on distress (or lack of distress) in rats and (2) To evaluate the level of distress in animals undergoing common husbandry or experimental procedures or "witnessing" these procedures being done on other animals. These studies will be conducted on 3-, 6- or 12-month old male and female rats of four commonly used outbred strains obtained from commercial vendors. Animals will be "instrumented" with a radio-telemetry transmitter to continuously monitor arterial blood pressures and heart rate or with a chronic, indwelling venous catheter to obtain sequential blood samples for the determination of plasma levels of stress related hormones (catecholamines, corticosterone and prolactin). Additional variables (weight gain, food and water consumption and estrous cyclicity) will also be monitored to gauge the physiologic status of the rats. The housing conditions to be evaluated are: isolated (single) housing, paired (double) housing, isolated housing with "chew" and "climbing/hiding" "toys" and isolated housing with access to a very enriched environment for a short period each day. Adaptation to the environmental housing conditions will also be evaluated. Common husbandry and experimental manipulations to which animals are to be exposed or witness being done on other animals will include: removal to a new cage, hand restraint and a s.c. injection, placement in a rodent restrainer for a short period with a tail vein injection, witnessing the decapitation of other animals and witnessing a tissue harvest from other animals. Although this project is a descriptive one and not hypothesis driven, it should provide very practical and important results that can be used by local IACUCs as they review animal protocols and by national organizations such as the PHS, AAALAC, ILAR and USDA as they promulgate requirements, guidelines and regulations in this area.