Data from: Measuring fecal testosterone in females and fecal estrogens in males: comparison of RIA and LC/MS/MS methods for wild baboons (Papio cynocephalus).

The development of non-invasive methods, particularly fecal determination, has made possible the assessment of hormone concentrations in wild animal populations. However, measuring fecal metabolites needs careful validation for each species and for each sex. We investigated whether radioimmunoassays (RIAs) previously used to measure fecal testosterone (fT) in male baboons and fecal estrogens (fE) in female baboons were well suited to measure these hormones in the opposite sex. We compared fE and fT concentrations determined by RIA to those measured by liquid chromatography combined with triple quadropole mass spectrometry (LC/MS/MS), a highly specific method. Additionally, we conducted a biological validation to assure that the measurements of fecal concentrations reflected physiological levels of the hormone of interest. Several tests produced expected results that led us to conclude that our RIAs can reliably measure fT and fE in both sexes, and that within-sex comparisons of these measures are valid: (i) fTRIA were significantly correlated to fTLC/MS/MS for both sexes; (ii) fTRIA were higher in adult than in immature males; (iii) fTRIA were higher in pregnant than non-pregnant females; (iv) fERIA were correlated with 17β-estradiol (fE2) and with estrone (fE1) determined by LC/MS/MS in pregnant females; (v) fERIA were significantly correlated with fE2 in non-pregnant females and nearly significantly correlated in males; (vi) fERIA were higher in adult males than in immature males. fERIA were higher in females than in males, as predicted, but unexpectedly, fTRIA were higher in females than in males, suggesting a difference in steroid metabolism in the two sexes; consequently, we conclude that while within-sex comparisons are valid, fTRIA should not be used for intersexual comparisons. Our results should open the field to important additional studies, as to date the roles of testosterone in females and estrogens in males have been little investigated.非侵入性检测技术的发展，尤其是粪便检测手段的进步，使得评估野生动物种群内激素浓度成为可能。然而，针对每一物种与每一种性别，粪便代谢物的检测均需开展严谨的方法学验证。本研究探讨了此前分别用于测定雄性狒狒粪便睾酮（fecal testosterone, fT）与雌性狒狒粪便雌激素（fecal estrogens, fE）的放射免疫分析法（radioimmunoassays, RIAs），是否适用于对相反性别的样本开展此类激素检测。 我们将放射免疫分析法测得的粪便雌激素与睾酮浓度，与液相色谱-三重四极杆串联质谱法（liquid chromatography combined with triple quadrupole mass spectrometry, LC/MS/MS）——一种高特异性检测方法——的测定结果进行了对比。此外，本研究还开展了生物学验证实验，以确保粪便激素浓度的检测结果能够反映目标激素的生理水平。 多项实验得到了预期结果，据此我们可得出结论：本研究使用的放射免疫分析法能够可靠地同时测定两种性别的粪便睾酮与粪便雌激素，且同性别内的激素水平对比具备有效性：(i) 两种性别的粪便睾酮放射免疫测定值（fT_RIA）均与液相色谱-质谱联用法测得的粪便睾酮值（fT_LC/MS/MS）显著相关；(ii) 成年雄性个体的粪便睾酮放射免疫测定值显著高于未成熟雄性个体；(iii) 怀孕雌性个体的粪便睾酮放射免疫测定值显著高于非怀孕雌性个体；(iv) 怀孕雌性个体的粪便雌激素放射免疫测定值（fE_RIA）与液相色谱-质谱联用法测得的17β-雌二醇（17β-estradiol, fE2）及雌酮（estrone, fE1）浓度均呈显著相关；(v) 非怀孕雌性个体的粪便雌激素放射免疫测定值与17β-雌二醇浓度显著相关，而雄性个体中两者的相关性接近显著水平；(vi) 成年雄性个体的粪便雌激素放射免疫测定值显著高于未成熟雄性个体。 正如预期，雌性个体的粪便雌激素放射免疫测定值高于雄性个体，但出乎意料的是，雌性个体的粪便睾酮放射免疫测定值也高于雄性个体，这提示两种性别在类固醇激素代谢方面存在差异。因此我们认为，尽管同性别内的激素水平对比具备有效性，但粪便睾酮放射免疫测定法不应被用于跨性别的激素水平比较。 截至目前，睾酮在雌性个体、雌激素在雄性个体中的生理作用鲜有研究，本研究结果可为后续相关重要研究的开展提供重要支撑。