Determination of testosterone and corticosterone in
feathers of barn swallows (Hirundo Rustica)
Z. Bílková1
, M. Kotasová Adámková2,3
, O. Tomášek3,4
, T. Albrecht3,4
, Z. Šimek1
1
Research Centre for Toxic Compounds in the Environment, Masaryk University, Brno, Czech Republic
2
Department of Botany and Zoology, Masaryk University, Brno, Czech Republic
3
Institute of Vertebrate Biology, Academy of Sciences, Studenec, Czech Republic
4
Department of Zoology, Charles University, Prague, Czech Republic
The level of endocrine mediators of individual fitness, such as stress hormones or sex
hormones is monitored in various matrices. Regarding the birds, testosterone and
corticosterone are usually measured in the blood plasma. Plasma sampling gives a snapshot of
the concentration of steroids and its metabolites at the time of capture. Concentration levels of
corticosterone culminate within several minutes after initiation of stress stimulus with
initiation of the increase sometimes in less than 3 minutes. Similarly, concentration level of
testosterone decreases with stress in association with elevated corticosterone. On the other
hand feathers gradually accumulate hormones during their growth. The measuring of hormone
levels in feather provides information about plasma hormone levels over a longer time period.
Therefore the analysis of feathers can offer valuable information about stress levels and
condition of an individual bird.
A new analytical method has been applied to assess the occurrence of the hormones
(testosterone and corticosterone) in bird feathers. Derivatization of target hormones was used
in order to significantly enhance the LC-ESI-MS/MS signal. The methanol extract of hormones
was cleaned-up by solid phase extraction and derivatized immediately before LC-ESI-MS/MS
analyses. The AmplifexTM
Keto Reagent kit was used for derivatization of hormones at keto
groups. This approach to the analysis significantly improves the identification of target
hormone in feather samples, distinctly enhances sensitivity of the analytical method and
decreases limits of detection.
Our study was focused on determination of feather steroids especially in barn swallow
(Hirundo Rustica). Feather from flanks were collected for analysis for hormone concentrations.
Birds from three isolated farms in South Bohemia, Czech Republic were caught for this
purpose.
Key words:
Feather, Steroids, Corticosterone, Testosterone, HPLC-ESI-MS/MS, Barn swallow (Hirundo Rustica)
Acknowledgment: Research was funded by GACR GA17-24782S