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，尤其是粪便测定法（fecal determination），为野生动物种群的激素浓度评估提供了可行途径。然而，粪便代谢物的检测需针对每一物种及每一性别进行严格验证。本研究探究了此前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）的放射免疫测定法（radioimmunoassays, RIAs）是否同样适用于异性样本的激素检测。本研究将放射免疫测定法测得的粪便雌激素与睾酮浓度，与高特异性检测方法——液相色谱-三重四极杆质谱联用法（liquid chromatography combined with triple quadrupole mass spectrometry, LC/MS/MS）的检测结果进行了对比。此外，本研究开展了生物学验证，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。多项检测得到了预期结果，据此我们可以得出结论：本研究使用的放射免疫测定法可稳定检测雌雄狒狒的粪便睾酮与雌激素浓度，且该方法用于同性别间的激素水平比较是可靠的：(1) 无论雌雄，放射免疫法粪便睾酮检测值（fTRIA）均与液相色谱-三重四极杆质谱联用法测得的粪便睾酮值（fTLC/MS/MS）显著相关；(2) 成年雄性个体的fTRIA值显著高于未成熟雄性个体；(3) 怀孕雌性个体的fTRIA值显著高于非怀孕雌性个体；(4) 怀孕雌性个体的放射免疫法粪便雌激素检测值（fERIA）与液相色谱-三重四极杆质谱联用法测得的17β-雌二醇（17β-estradiol, fE2）及雌酮（estrone, fE1）浓度均呈相关关系；(5) 非怀孕雌性个体的fERIA值与fE2显著相关，雄性个体的该相关关系接近显著水平；(6) 成年雄性个体的fERIA值显著高于未成熟雄性个体。正如预期，雌性个体的fERIA值高于雄性个体，但出乎意料的是，雌性个体的fTRIA值同样高于雄性个体，这提示雌雄个体的类固醇代谢存在差异；因此我们认为，尽管该方法可用于同性别间的激素水平比较，但放射免疫法测得的粪便睾酮值不可用于跨性别的激素水平比较。截至目前，睾酮在雌性个体及雌激素在雄性个体中的生理作用尚未得到充分研究，本研究结果可为该领域后续的重要拓展研究提供契机。