title: Validation of salivary cortisol and testosterone assays in chimpanzees by liquid chromatography-tandem mass spectrometry.
abstract: Owing to its high temporal sensitivity, saliva has distinct advantages for measuring steroids, compared with other noninvasive samples such as urine and feces. Here, we report the validity of assaying salivary cortisol (C) and testosterone (T) using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in captive male chimpanzees, Pan troglodytes. For both the C and T concentrations, we found positive relationships between saliva and plasma. The concentrations of C and T in saliva showed clear patterns of diurnal fluctuation, whereas those in urine and feces did not. These results suggest that the salivary steroid concentrations can be regarded as good indicators of circulating steroid levels. We also developed and validated an efficient method for collecting saliva samples from cotton rope. Although rope includes inherent steroid-like compounds and may affect the accuracy of steroid measurements, our rope-washing procedures effectively removed intrinsic steroidal materials. There was a significant association between the C and T concentrations measured from saliva collected from rope licked by the chimpanzees and those measured from saliva collected directly from the mouth. Salivary T values estimated by LC/MS-MS were similar to those measured by radioimmunoassay. The results indicate the usefulness of saliva as a noninvasive steroid measure and that steroids in the saliva of chimpanzees can be accurately measured by LC-MS/MS.
authors.affiliation: Department of Evolutionary Studies of Biosystems, The Graduate University for Advanced Studies, Hayama, Kanagawa, Japan. kutsu@soken.ac.jp
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kutsukake
authors.forename: Koki
authors.initials: K
authors.lastname: Ikeda
authors.forename: Seijiro
authors.initials: S
authors.lastname: Honma
authors.forename: Migaku
authors.initials: M
authors.lastname: Teramoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Mori
authors.forename: Ikuo
authors.initials: I
authors.lastname: Hayasaka
authors.forename: Rain
authors.initials: R
authors.lastname: Yamamoto
authors.forename: Takafumi
authors.initials: T
authors.lastname: Ishida
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yoshikawa
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Hasegawa
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D002940:Circadian Rhythm; D005243:Feces / Q000737:chemistry; D006854:Hydrocortisone / Q000032:analysis* / Q000097:blood / Q000652:urine; D008297:Male; D002679:Pan troglodytes / Q000378:metabolism*; D011863:Radioimmunoassay; D012463:Saliva / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods / Q000662:veterinary; D053719:Tandem Mass Spectrometry; D013739:Testosterone / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D013739:Testosterone; D006854:Hydrocortisone