Repozitorij Univerze v Novi Gorici

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju

Opcije:
  Ponastavi


1 - 2 / 2
Na začetekNa prejšnjo stran1Na naslednjo stranNa konec
1.
ASSESSMENT OF CORTISOL AND DHEA CONCENTRATIONS IN THE GRIFFON VULTURE (Gyps fulvus) FEATHERS TO EVALUATE ITS HEALTH CONDITION
Gian Nicola Frongia, Tanja Peric, Marco Muzzeddu, Fiammetta Berlinguer, Giovanni Leoni, Valentina Satta, Cristina Bergamin, Marcello Franchini, Antonella Comin, Salvatore Naitana, Alberto Prandi, 2018, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: During their life, birds face several challenges which can threaten the stability of physiological functions. These situations typically trigger a cascade of endocrine secretions involving the hypothalamic–pituitary–adrenal (HPA) axis, and resulting in the release of both cortisol and corticosterone also in birds. The use of a non-invasive approach to collect samples of biological material derived from natural populations represents a greatly combination for an improvement of knowledge avoiding handling animals. Steroid concentrations in feathers are mainly acquired from the capillary around the follicle during the long period of feather grown reflecting their bloodstream concentrations. Accordingly, a chronic HPA axis activation could be assessed using molted feathers cortisol concentrations. Another hormone, dehydroepiandrosterone (DHEA), is secreted by adrenals and it could be assessed in molted feathers. This study was aimed to evaluate the feasibility of using feathers cortisol and DHEA concentrations to provide a retrospective assessment of the activity of the HPA axis in griffon vulture acquired for health monitoring purposes. For this, we introduced two groups of animals with a known health condition: one group composed by griffons that have experienced a long-term physiologically compromised period (PC group; n=8) and the other group composed by griffons physiologically not compromised (CTRL group; n=9). The feathers cortisol and DHEA analyses were carried out using RIA [1,2] adapted for feathers. The results revealed different feather hormone concentrations between the two groups of animals. The feathers cortisol had a median value higher in the PC group than in the CTRL group, with cortisol concentrations showing a central value 1.6 times higher in those animals that suffered a long-term physiological impairment. The PC group showed also (Kruskal- Wallis test) higher feather concentrations of DHEA (P=0.01) than the CTRL group. Pearson’s correlation coefficients were used to examine the associations between cortisol and DHEA, showing no correlation between cortisol and DHEA feather concentrations in the PC group (r=0.18, P=0.34) and a moderate positive correlation in the CTRL group (r=0.51, P=0.011). In conclusion, our study reveals that molted feathers can be an interesting way to evaluate the physiological status of wild animals by using a non-invasive approach. Our analyses reveal that in addition to cortisol also DHEA could be evaluated to better understand the relationships between these hormones and to determine the resilience condition of wild species.
Najdeno v: osebi
Ključne besede: CORTISOL, DHEA, GRIFFON VULTURE, Gyps fulvus, FEATHER
Objavljeno: 09.04.2019; Ogledov: 228; Prenosov: 0
.pdf Polno besedilo (4,05 MB)

2.
Assessment of cortisol and DHEA concentrations in Griffon vulture (Gyps fulvus) feathers to evaluate its allostatic load
Gian Nicola Frongia, Tanja Peric, 2019, izvirni znanstveni članek

Opis: The use of a non-invasive approach to collect biological samples from natural populations represents a great means of gathering information while avoiding handling animals. Even if corticosterone is the main glucocorticoid investigated in birds, it has been observed a proportional direct link between corticosterone and cortisol concentrations. Dehydroepiandrosterone (DHEA) can be produced by the adrenal cortex and should have prominent antiglucocorticoid properties also in birds. The aim of this study was to verify if there is any difference in the cortisol and DHEA feather concentrations between clinically normal and physiologically compromised Griffon vultures (Gyps fulvus) through the non-invasive approach of collecting moulted feathers without having to pluck them from the bird. The study was carried out using 8 physiologically compromised (PC) Griffons and 9 clinically normal Griffons considered as the control (CTRL) group that were necropsied or from the wildlife rehabilitation centre. Primary and secondary covert feathers were either collected directly from the birds’ cage floors, or, in the case of dead Griffons, they were plucked off the animals. The results, obtained by RIA, revealed that both cortisol (P<0.01) and DHEA (P<0.05) feather concentrations were higher in the PC than in the CTRL group. No difference was observed by comparing the cortisol/DHEA ratio between the two evaluated groups (P=0.15). Pearson’s correlation coefficients showed no correlation between feather hormone concentrations in the PC group (r=0.01, P=0.96) while a positive correlation in the CTRL group (r=0.65, P=0.006) was observed. In conclusion, our study reveals that moulted feathers can be a non-invasive and an interesting tool to evaluate the allostatic load of wild birds and they allowed to better understand the relationship between hormones of the hypothalamic–pituitary–adrenal axis and the physiological status of the birds.
Najdeno v: osebi
Ključne besede: wild birds, raptors, HPA axis, steroids, coverts
Objavljeno: 16.09.2019; Ogledov: 173; Prenosov: 3
.pdf Polno besedilo (664,32 KB)

Iskanje izvedeno v 0 sek.
Na vrh