TY - JOUR
T1 - Altered hormone levels and circadian rhythm of activity in the WKY rat, a putative animal model of depression
AU - Solberg, Leah C.
AU - Olson, Susan Losee
AU - Turek, Fred W.
AU - Redei, Eva
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2001
Y1 - 2001
N2 - The Wistar Kyoto (WKY) rat is hyperreactive to stress and exhibits depressive-like behavior in several standard behavioral tests. Because patients with depressive disorders often exhibit disruptions in the circadian rhythm of activity, as well as altered secretory patterns of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid hormones, we tested the hypothesis that these phenomena occur in the WKY rat. Plasma ACTH and corticosterone levels remained significantly higher after the diurnal peak for several hours in WKY rats relative to Wistar rats. Also, plasma levels of thyroid-stimulating hormone were significantly higher in WKY relative to Wistar rats across the 24-h period, despite normal or slightly higher levels of 3,5,3′-triiodothyronine. In addition, under constant darkness conditions, WKY rats exhibited a shorter free running period and a decreased response to a phase-delaying light pulse compared with Wistar rats. In several ways these results are similar to those seen in other animal models of depression as well as in depressed humans, suggesting that the WKY rat could be used to investigate the genetic basis for these abnormalities.
AB - The Wistar Kyoto (WKY) rat is hyperreactive to stress and exhibits depressive-like behavior in several standard behavioral tests. Because patients with depressive disorders often exhibit disruptions in the circadian rhythm of activity, as well as altered secretory patterns of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid hormones, we tested the hypothesis that these phenomena occur in the WKY rat. Plasma ACTH and corticosterone levels remained significantly higher after the diurnal peak for several hours in WKY rats relative to Wistar rats. Also, plasma levels of thyroid-stimulating hormone were significantly higher in WKY relative to Wistar rats across the 24-h period, despite normal or slightly higher levels of 3,5,3′-triiodothyronine. In addition, under constant darkness conditions, WKY rats exhibited a shorter free running period and a decreased response to a phase-delaying light pulse compared with Wistar rats. In several ways these results are similar to those seen in other animal models of depression as well as in depressed humans, suggesting that the WKY rat could be used to investigate the genetic basis for these abnormalities.
KW - Forced swim test
KW - Hypothalamic-pituitary-adrenal axis
KW - Hypothalamic-pituitary-thyroid axis
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U2 - 10.1152/ajpregu.2001.281.3.r786
DO - 10.1152/ajpregu.2001.281.3.r786
M3 - Article
C2 - 11506993
AN - SCOPUS:0034833028
VL - 281
SP - R786-R794
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0363-6119
IS - 3 50-3
ER -