Faculté de Médecine Vétérinaire, Boulevard de Colonster, Liège, Belgium.
Equine Vet J. 2011 Jul;43(4):487-93. doi: 10.1111/j.2042-3306.2010.00294.x. Epub 2010 Sep 29.
In horses, serum cortisol concentration is considered to provide an indirect measurement of stress. However, it includes both free and bound fractions. The sampling method is also invasive and often stressful. This is not the case for salivary cortisol, which is collected using a more welfare-friendly method and represents a part of the free cortisol fraction, which is the biologically active form.
To compare salivary and serum cortisol assays in horses, in a wide range of concentrations, using an adrenocorticotropic hormone (ACTH) stimulation test, in order to validate salivary cortisol for stress assessment in horse.
In 5 horses, blood samples were drawn using an i.v. catheter. Saliva samples were taken using swabs. Cortisol was assayed by radioimmunoassay. All data were treated with a regression method, which pools and analyses data from multiple subjects for linear analysis.
Mean ± s.d. cortisol concentrations measured at rest were 188.81 ± 51.46 nmol/l in serum and 1.19 ± 0.54 nmol/l in saliva. They started increasing immediately after ACTH injection and peaks were reached after 96 ± 16.7 min in serum (356.98 ± 55.29 nmol/l) and after 124 ± 8.9 min in saliva (21.79 ± 7.74 nmol/l, P<0.05). Discharge percentages were also different (225% in serum and 2150% in saliva, P<0.05). Correlation between serum and salivary cortisol concentrations showed an adjusted r(2) = 0.80 (P<0.001). The strong link between serum and salivary cortisol concentrations was also estimated by a regression analysis.
The reliability of both RIAs and regression found between serum and salivary cortisol concentrations permits the validation of saliva-sampling as a noninvasive technique for cortisol level assessment in horses.
在马中，血清皮质醇浓度被认为是应激的间接测量指标。然而，它包含游离和结合两部分。采样方法也是侵入性的，通常会带来压力。唾液皮质醇则不同，它采用了更符合动物福利的方法采集，代表了游离皮质醇部分，即具有生物活性的形式。
使用促肾上腺皮质激素（ACTH）刺激试验比较马在广泛浓度范围内的唾液和血清皮质醇检测，以验证唾液皮质醇在马应激评估中的应用。
在 5 匹马中，通过静脉导管采集血液样本，使用拭子采集唾液样本。通过放射免疫分析法检测皮质醇。所有数据均采用回归法处理，该方法汇集并分析多个个体的数据进行线性分析。
在休息时，血清和唾液中皮质醇的平均浓度±标准差分别为 188.81±51.46 nmol/L 和 1.19±0.54 nmol/L。在 ACTH 注射后立即开始增加，血清中的峰值在 96±16.7 min 时达到（356.98±55.29 nmol/L），唾液中的峰值在 124±8.9 min 时达到（21.79±7.74 nmol/L，P<0.05）。排泄百分比也不同（血清中为 225%，唾液中为 2150%，P<0.05）。血清和唾液皮质醇浓度之间的相关性显示调整后的 r(2)=0.80（P<0.001）。通过回归分析也估计了血清和唾液皮质醇浓度之间的强关联性。
两种 RIA 和回归分析之间的可靠性允许验证唾液采样作为评估马皮质醇水平的非侵入性技术。
