Isolation stress impacts Met-enkephalin in the hypothalamo-pituitary-adrenocortical axis in growing Polish Mountain sheep: a possible role of the opioids in modulation of HPA axis
Krystyna Koziec , Marta Dziedzicka-Wasylewska , Colin G. Scanes
AbstractIt was hypothesized that there is cross-talk between the classical constituents of the hypothalamo-pituitary-adrenocortical axis (HPA) and Met-enkephalin in the HPA axis. The study examined effects of isolation stress, sex, and age on concentrations of native Met-enkephalin and pro-enkephalin (PENK) gene expression in tissues of the HPA (hypothalamus, pituitary gland and adrenal cortex) in 3-, 6- and 9-month old female and male lambs. In addition, the effects of isolation stress on in vitro release Met-enkephalin from fragments of the hypothalamus or adrenal cortex were examined. Isolation stress was followed by decreases in the concentration of Met-enkephalin in both the pituitary gland and adrenal cortex. There were also increases in the hypothalamic concentration of Met-enkephalin together with increases in PENK gene expression in the HPA in 6- and 9-months old females and males. There were reductions in release of Met-enkephalin from hypothalamic and adrenocortical tissue in vitro after isolation stress. In the presence of naltrexone, there were increases in basal release in vitro of Met-enkephalin from hypothalamic tissue from control and stressed female lambs but a decrease in tissue from stressed male lambs. In a somewhat similar manner, the presence of naltrexone was associated with increases in the basal release of Met-enkephalin from adrenocortical tissue from control female lambs but a decrease with tissue from stressed female and both stressed and control male lambs.
|Journal series||Stress: The International Journal on the Biology of Stress, [Stress: the International Journal on Biology of Stress], ISSN 1025-3890, e-ISSN 1607-8888, (N/A 70 pkt)|
|Publication size in sheets||0.5|
|Keywords in English||Isolation stress, tissue Met-enkephalin, in vitro enkephalin release, PENK mRNA, hypothalamo-pituitary axis|
|ASJC Classification||; ; ; ;|
|Publication indicators||: 2017 = 0.88; : 2018 = 2.168 (2) - 2018=2.853 (5)|
|Finansowanie||This work was supported by the National Centre for Research and Development (PL); under Grant no. 12006406; University of Agriculture Research Funding under Grant 3243/DAPE/2016-2017.|
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