Department of Experimental Psychology, Institute of Psychology, University of São Paulo, Av. Prof. Mello Moraes, 1721, Cidade Universitária, São Paulo, 05508-030, Brazil.
J Comp Physiol B. 2010 Aug;180(6):919-25. doi: 10.1007/s00360-010-0467-9. Epub 2010 Mar 25.
We verified the relevance of measuring fecal glucocorticoid metabolites (FGM) to assess the stress response of the Syrian hamster. Male and female hamsters (n = 10 each) were submitted to an adrenocorticotropic hormone (ACTH) challenge test, whereas animals in the control group received 0.5 mL of sterile isotonic saline solution. All feces voided by each animal were collected at 4 h intervals from 24 h before (baseline) until 48 h after injections. FGM were quantified using an 11-oxoetiocholanolone enzyme immunoassay (EIA). Basal concentrations of FGM were almost four times higher in males than in females. Following ACTH administration, FGM levels started rising from 8 h onwards, reaching peak concentrations 20 or 28 h post injection in males and females, respectively. Despite the much higher absolute concentrations present in males, the relative increase (500%) in response to the ACTH stimulation was similar in both sexes. Sex differences in FGM levels are in accordance with results reported by others regarding the hamster adrenal physiology. The comparison of the adrenocortical response of males and females to an ACTH challenge provided new information about the amplitude and the timing of such a response and the excretion of glucocorticoids in both sexes. We demonstrated for the first time in the Syrian hamster that adrenocortical activity can be monitored in fecal samples in a noninvasive way. Our study provides a humane, practical, and noninvasive alternative to blood removal and therefore a powerful tool for stress-related studies in a species frequently used as an animal model in medical research.
我们验证了测量粪便皮质激素代谢物（FGM）来评估叙利亚仓鼠应激反应的相关性。雄性和雌性仓鼠（每组各 10 只）接受促肾上腺皮质激素（ACTH）挑战测试，而对照组动物接受 0.5 mL 无菌等渗盐水。从注射前 24 小时（基线）到注射后 48 小时，每隔 4 小时收集每个动物排出的所有粪便。使用 11-氧代去甲雄烷酮酶免疫测定法（EIA）定量 FGM。FGM 的基础浓度在雄性中几乎是雌性的四倍。在 ACTH 给药后，FGM 水平从 8 小时开始上升，分别在雄性和雌性中达到注射后 20 或 28 小时的峰值浓度。尽管雄性中存在更高的绝对浓度，但对 ACTH 刺激的相对增加（500%）在两性中相似。FGM 水平的性别差异与其他人关于仓鼠肾上腺生理学的报告结果一致。雄性和雌性对 ACTH 挑战的肾上腺皮质反应的比较提供了有关这种反应的幅度和时间以及两性中糖皮质激素排泄的新信息。我们首次在叙利亚仓鼠中证明，通过非侵入性方式可以监测粪便样本中的肾上腺皮质活性。我们的研究为在经常作为医学研究动物模型的物种中去除血液提供了一种人道、实用和非侵入性的替代方法，是一种与应激相关研究的有力工具。
