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Measuring Faecal Epi-Androsterone as an Indicator of Gonadal Activity in Spotted Hyenas (Crocuta crocuta).

Pribbenow S, East ML, Ganswindt A, Tordiffe AS, Hofer H, Dehnhard M - PLoS ONE (2015)

Bottom Line: Our results showed that β-glucuronidases from both sources produced similar results from spotted hyena faeces.The biological relevance of the epiandrosterone EIA was validated by demonstrating (1) a significant increase in fTM levels in response to a testosterone injection within 16 h, (2) no biological responsiveness to an adrenocorticotropic hormone (ACTH) injection and (3) significant differences in fTM levels between juvenile males and adult immigrant males in a free-ranging wild population.Our results clearly demonstrate that the epiandrosterone EIA is a reliable non-invasive method to monitor gonadal activity in spotted hyenas.

View Article: PubMed Central - PubMed

Affiliation: Department Reproduction Biology and Evolutionary Ecology, Leibniz Institute of Zoo and Wildlife Research, Forschungsverbund Berlin e.V., Berlin, Germany.

ABSTRACT
Enzyme immunoassays (EIA) that measure faecal testosterone metabolites (fTM) are useful tools to monitor gonadal activity. The aim of this study was to validate an "in-house" epiandrosterone EIA to monitor fTM in spotted hyenas. FTM were characterised in a male and a female hyena that each received an injection of 3H-testosterone. High-performance liquid chromatography (HPLC) analyses revealed a cluster of highly polar enzyme-hydrolysable hormone metabolite conjugates. We performed hydrolysis using β-glucuronidase to deconjugate metabolites and improve sensitivity of the assay. Because β-glucuronidase from Helix pomatia has been reported to bias testosterone measurements in some species, we compared the enzymatic activity of the commonly used β-glucuronidase extracted from H. pomatia with the same enzyme from Escherichia coli. Our results showed that β-glucuronidases from both sources produced similar results from spotted hyena faeces. We therefore hydrolysed samples with H. pomatia enzymes. HPLC analyses also demonstrated that following hydrolysis the epiandrosterone EIA measured significant amounts of immunoreactive metabolites corresponding to radiolabelled metabolites in both sexes. Additionally, HPLC and GC-MS analyses confirmed the presence of epiandrosterone in faeces of spotted hyenas. The biological relevance of the epiandrosterone EIA was validated by demonstrating (1) a significant increase in fTM levels in response to a testosterone injection within 16 h, (2) no biological responsiveness to an adrenocorticotropic hormone (ACTH) injection and (3) significant differences in fTM levels between juvenile males and adult immigrant males in a free-ranging wild population. Our results clearly demonstrate that the epiandrosterone EIA is a reliable non-invasive method to monitor gonadal activity in spotted hyenas.

No MeSH data available.


Related in: MedlinePlus

Hormonal data of juvenile and adult immigrant male hyenas.FTM concentrations (ng/g faeces) in juvenile male (n = 15) and adult male (n = 15) spotted hyenas determined in the epiandrosterone EIA following hydrolysis with β-glucuronidase from Helix pomatia. The * indicates a significant difference between both categories.
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pone.0128706.g008: Hormonal data of juvenile and adult immigrant male hyenas.FTM concentrations (ng/g faeces) in juvenile male (n = 15) and adult male (n = 15) spotted hyenas determined in the epiandrosterone EIA following hydrolysis with β-glucuronidase from Helix pomatia. The * indicates a significant difference between both categories.

Mentions: To confirm the physiological importance of faecal testosterone metabolite analyses, we compared fTM levels between adult immigrant male and juvenile male spotted hyenas (Fig 8). Adult immigrant male spotted hyenas possessed significantly higher fTM levels than male juveniles (Fligner-Policelli test, U = 2.3208, exact p using 10,000 Monte Carlo simulations = 0.0294; permutation test, test statistic = -8.349, p = 0.0087). In juvenile males, fTM levels ranged from 272.7 to 1295.05 ng/g wet faeces and in adult immigrant males from 179.3 to 4259.75 ng/g wet faeces, indicating high inter-individual variation.


Measuring Faecal Epi-Androsterone as an Indicator of Gonadal Activity in Spotted Hyenas (Crocuta crocuta).

Pribbenow S, East ML, Ganswindt A, Tordiffe AS, Hofer H, Dehnhard M - PLoS ONE (2015)

Hormonal data of juvenile and adult immigrant male hyenas.FTM concentrations (ng/g faeces) in juvenile male (n = 15) and adult male (n = 15) spotted hyenas determined in the epiandrosterone EIA following hydrolysis with β-glucuronidase from Helix pomatia. The * indicates a significant difference between both categories.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4481319&req=5

pone.0128706.g008: Hormonal data of juvenile and adult immigrant male hyenas.FTM concentrations (ng/g faeces) in juvenile male (n = 15) and adult male (n = 15) spotted hyenas determined in the epiandrosterone EIA following hydrolysis with β-glucuronidase from Helix pomatia. The * indicates a significant difference between both categories.
Mentions: To confirm the physiological importance of faecal testosterone metabolite analyses, we compared fTM levels between adult immigrant male and juvenile male spotted hyenas (Fig 8). Adult immigrant male spotted hyenas possessed significantly higher fTM levels than male juveniles (Fligner-Policelli test, U = 2.3208, exact p using 10,000 Monte Carlo simulations = 0.0294; permutation test, test statistic = -8.349, p = 0.0087). In juvenile males, fTM levels ranged from 272.7 to 1295.05 ng/g wet faeces and in adult immigrant males from 179.3 to 4259.75 ng/g wet faeces, indicating high inter-individual variation.

Bottom Line: Our results showed that β-glucuronidases from both sources produced similar results from spotted hyena faeces.The biological relevance of the epiandrosterone EIA was validated by demonstrating (1) a significant increase in fTM levels in response to a testosterone injection within 16 h, (2) no biological responsiveness to an adrenocorticotropic hormone (ACTH) injection and (3) significant differences in fTM levels between juvenile males and adult immigrant males in a free-ranging wild population.Our results clearly demonstrate that the epiandrosterone EIA is a reliable non-invasive method to monitor gonadal activity in spotted hyenas.

View Article: PubMed Central - PubMed

Affiliation: Department Reproduction Biology and Evolutionary Ecology, Leibniz Institute of Zoo and Wildlife Research, Forschungsverbund Berlin e.V., Berlin, Germany.

ABSTRACT
Enzyme immunoassays (EIA) that measure faecal testosterone metabolites (fTM) are useful tools to monitor gonadal activity. The aim of this study was to validate an "in-house" epiandrosterone EIA to monitor fTM in spotted hyenas. FTM were characterised in a male and a female hyena that each received an injection of 3H-testosterone. High-performance liquid chromatography (HPLC) analyses revealed a cluster of highly polar enzyme-hydrolysable hormone metabolite conjugates. We performed hydrolysis using β-glucuronidase to deconjugate metabolites and improve sensitivity of the assay. Because β-glucuronidase from Helix pomatia has been reported to bias testosterone measurements in some species, we compared the enzymatic activity of the commonly used β-glucuronidase extracted from H. pomatia with the same enzyme from Escherichia coli. Our results showed that β-glucuronidases from both sources produced similar results from spotted hyena faeces. We therefore hydrolysed samples with H. pomatia enzymes. HPLC analyses also demonstrated that following hydrolysis the epiandrosterone EIA measured significant amounts of immunoreactive metabolites corresponding to radiolabelled metabolites in both sexes. Additionally, HPLC and GC-MS analyses confirmed the presence of epiandrosterone in faeces of spotted hyenas. The biological relevance of the epiandrosterone EIA was validated by demonstrating (1) a significant increase in fTM levels in response to a testosterone injection within 16 h, (2) no biological responsiveness to an adrenocorticotropic hormone (ACTH) injection and (3) significant differences in fTM levels between juvenile males and adult immigrant males in a free-ranging wild population. Our results clearly demonstrate that the epiandrosterone EIA is a reliable non-invasive method to monitor gonadal activity in spotted hyenas.

No MeSH data available.


Related in: MedlinePlus