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.

Nrk, an X-linked Protein Kinase in the Germinal Center Kinase Family, Is Required for Placental Development and Fetoplacental Induction of Labor

“…Measurements using LC-MS/MS (20,21) (Fig. 8A) and ELISA (data not shown) both showed that similar in WT dams carrying WT fetuses, a drastic decrease in the progesterone level was observed in Nrk-null dams carrying Nrk-null fetuses: whereas the level ranged between ϳ20 and ϳ100 ng/ml at 17.5 dpc, it ranged between ϳ1 and ϳ2 ng/ml in five of seven mice at 19.5 dpc.…”

Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) Assay for Simultaneous Measurement of Salivary Testosterone and Cortisol in Healthy Men for Utilization in the Diagnosis of Late-onset Hypogonadism in Males

“…the methods used for LC-Ms/Ms device were essentially similar to those described previously [9,24]. Specificity: Zero saliva (1 mL) and serum (0.1 mL) from healthy males (1 mL) were extracted, as described above.…”

“…Saliva T level are ~ 100 pg/mL or less and the steroid-binding protein levels are low; therefore, adsorption to instruments is a problem. When a linen rope is used for chimpanzee saliva collection, the rate of F adsorption is approximately 10% [9,29]. Furthermore, cotton used in a container for We developed a method for simultaneous quantification of T and F in saliva using LC-MS/MS [9,24], which has high specificity, sensitivity, and accuracy in the micro-quantification of steroid hormones.…”

“…When a linen rope is used for chimpanzee saliva collection, the rate of F adsorption is approximately 10% [9,29]. Furthermore, cotton used in a container for We developed a method for simultaneous quantification of T and F in saliva using LC-MS/MS [9,24], which has high specificity, sensitivity, and accuracy in the micro-quantification of steroid hormones. In the present study, the absolute range of saliva T was 50 to 130 pg/mL early in the morning and 40 to 90 pg/ mL during daytime.…”

“…Recent studies reported t and F in saliva were useful for evaluating bioavailability and accurately reflected serum hormone activity [1,3,[5][6][7][8]. Some studies indicated the measurement of salivary hormone levels facilitated the evaluation of precise physiologic actions based on free hormone activity, which could not be confirmed based on total blood hormone levels [1,3,6,9]. therefore, salivary hormone measurements have re-filling) for solid-phase extraction was purchased from Varian Inc (CA, USA).…”