Cinque Carlo, Zinni Manuela, Zuena Anna Rita, Giuli Chiara, Alemà Sebastiano G, Catalani Assia, Casolini Paola, Cozzolino Roberto
Fondazione EthoikosRadicondoli, Italy
Department of Physiology and Pharmacology V. ErspamerSapienza University of Rome, Rome, Italy.
Endocr Connect. 2018 Feb;7(2):250-257. doi: 10.1530/EC-17-0338. Epub 2018 Jan 4.
Knowledge of animals' hormonal status is important for conservation studies in wild or semi-free-ranging conditions as well as for behavioural and clinical experiments conducted in laboratory research, mostly performed on rats and mice. Faecal sampling is a useful non-invasive method to obtain steroid hormone assessments. Nevertheless, in laboratory studies, unlike other contexts, faecal sampling is less utilised. One of the issues raised is the necessity to collect samples belonging to different animals, separately. Usually, researchers using faecal sampling solve this problem through the isolation of animals or taking the cage rather than single animal as unit of study. These solutions though, could lead to unreliable measurements, and cannot be applied in many studies. Our aim was to show the biological reliability of individual faecal corticosterone metabolite (FCM) assessments in socially housed male and female Wistar rats. We analytically validated the enzyme immunoassay kit used for FCM assessments. Then, we exposed the animals to two different stress stimuli that are known to activate the hypothalamus-pituitary-adrenal axis and the following release of corticosterone to biologically validate the EIA kit: environmental enrichment and predator odour. Individual faecal sampling from social animals was collected through short-time handling. The results demonstrated that both the stimuli increased FCM levels in male and female rats showing the reliability of EIA kit assessment and the applicability of our sampling method. We also found a diurnal rhythm in FCM levels. These results could help to increase the use of faecal hormone metabolite determinations in studies conducted on rats.
了解动物的激素状态对于野生或半自由放养条件下的保护研究以及实验室研究中的行为和临床实验都很重要，这些实验大多以大鼠和小鼠为对象。粪便采样是一种获取类固醇激素评估的有用的非侵入性方法。然而，在实验室研究中，与其他情况不同，粪便采样的使用较少。提出的问题之一是需要分别收集属于不同动物的样本。通常，使用粪便采样的研究人员通过隔离动物或将笼子而不是单个动物作为研究单位来解决这个问题。然而，这些解决方案可能导致测量结果不可靠，并且不能应用于许多研究中。我们的目的是展示在群居的雄性和雌性Wistar大鼠中进行个体粪便皮质酮代谢物（FCM）评估的生物学可靠性。我们对用于FCM评估的酶免疫分析试剂盒进行了分析验证。然后，我们让动物暴露于两种已知会激活下丘脑-垂体-肾上腺轴并随后释放皮质酮的不同应激刺激下，以对酶免疫分析试剂盒进行生物学验证：环境富集和捕食者气味。通过短时间处理从群居动物中采集个体粪便样本。结果表明，两种刺激均增加了雄性和雌性大鼠的FCM水平，表明酶免疫分析试剂盒评估的可靠性以及我们采样方法的适用性。我们还发现FCM水平存在昼夜节律。这些结果可能有助于增加粪便激素代谢物测定在大鼠研究中的应用。
