TY - JOUR
T1 - Comparison of hair steroid levels among Wistar rats exposed to different environmental enrichment settings
AU - Elmi, Alberto
AU - Vannetti, Niccolò I.
AU - Galligioni, Viola
AU - Govoni, Nadia
AU - Aniballi, Camilla
AU - Sánchez-Morgado, José M.
AU - Bacci, Maria L.
AU - Ventrella, Domenico
N1 - Publisher Copyright:
© Elmi, et al.
PY - 2024/12
Y1 - 2024/12
N2 - Background and Aim: Environmental enrichment (EE) is a pivotal tool for creating ideal housing conditions that allow animals to fully display their ethograms. At the micro-environmental level, they should elicit cognitive and social responses and increase physical activities. Hair steroids may be among the best biomarkers to evaluate the effects of prolonged exposure to different enrichments because they are non-invasive and provide information regarding a longer period. This study aimed to compare the hair steroid profiles, specifically corticosterone, cortisol, and dehydroepiandrosterone (DHEA), of Wistar rats exposed to two different EE settings. Materials and Methods: Twenty (n = 20) outbred Wistar rats were enrolled in this study. First hair collection (T0) was performed 3 days before weaning (at 28 days of life), and then Wistar rats were randomly divided into two equal groups with a sex ratio of 1:1: standard EE group, provided with one rat tunnel, and extra EE group, provided with an additional tunnel hanging from the top of the cage. Environmental conditions were 20°C-24°C, 45%-65% relative humidity, and a 12:12 dark/light cycle, with water and pelleted diet ad libitum. The rats were housed in ventilated cages with poplar bedding and nesting material. Hair was sampled again after 3 months (T1). Steroids were quantified using radioimmunoassay or enzyme-linked immunosorbent assay after methanol extraction. Results: Cortisol was not quantifiable, while corticosterone and DHEA were. After 3 months of exposure (T1), no differences were noted between the experimental groups. On data categorization per sex, females showed higher levels of all steroids than males. In males, the extra EE group had higher corticosterone levels. Conclusion: This study showed that corticosterone and DHEA are quantifiable in rats' hair, yet bigger datasets are needed to better understand the physiological levels of these hormones in such a matrix. Different enrichment settings induced differences between and within sex.
AB - Background and Aim: Environmental enrichment (EE) is a pivotal tool for creating ideal housing conditions that allow animals to fully display their ethograms. At the micro-environmental level, they should elicit cognitive and social responses and increase physical activities. Hair steroids may be among the best biomarkers to evaluate the effects of prolonged exposure to different enrichments because they are non-invasive and provide information regarding a longer period. This study aimed to compare the hair steroid profiles, specifically corticosterone, cortisol, and dehydroepiandrosterone (DHEA), of Wistar rats exposed to two different EE settings. Materials and Methods: Twenty (n = 20) outbred Wistar rats were enrolled in this study. First hair collection (T0) was performed 3 days before weaning (at 28 days of life), and then Wistar rats were randomly divided into two equal groups with a sex ratio of 1:1: standard EE group, provided with one rat tunnel, and extra EE group, provided with an additional tunnel hanging from the top of the cage. Environmental conditions were 20°C-24°C, 45%-65% relative humidity, and a 12:12 dark/light cycle, with water and pelleted diet ad libitum. The rats were housed in ventilated cages with poplar bedding and nesting material. Hair was sampled again after 3 months (T1). Steroids were quantified using radioimmunoassay or enzyme-linked immunosorbent assay after methanol extraction. Results: Cortisol was not quantifiable, while corticosterone and DHEA were. After 3 months of exposure (T1), no differences were noted between the experimental groups. On data categorization per sex, females showed higher levels of all steroids than males. In males, the extra EE group had higher corticosterone levels. Conclusion: This study showed that corticosterone and DHEA are quantifiable in rats' hair, yet bigger datasets are needed to better understand the physiological levels of these hormones in such a matrix. Different enrichment settings induced differences between and within sex.
KW - 3Rs
KW - biomarker
KW - environmental enrichment
KW - Rattus norvegicus
KW - refinement
KW - steroid
KW - welfare
UR - http://www.scopus.com/inward/record.url?scp=85211608936&partnerID=8YFLogxK
U2 - 10.14202/vetworld.2024.2731-2735
DO - 10.14202/vetworld.2024.2731-2735
M3 - Article
AN - SCOPUS:85211608936
SN - 0972-8988
VL - 17
SP - 2731
EP - 2735
JO - Veterinary World
JF - Veterinary World
IS - 12
ER -