Effects of odorants on the hypothalamic-pituitary-adrenal axis and interleukin-6 (IL-6) and IL-6 receptor mRNA expression in rat hypothalamus after restraint stress.
We recently reported that stress alters interleukin (IL)-6 and IL-6 receptor (IL-6R) mRNA levels in the hypothalamus. Odorants are reported to exert anti-stress effects. The aim of our study was to determine the effects of odorants on IL-6 and IL-6R mRNA expression in the hypothalamus, using reverse transcriptase-polymerase chain reaction and on serum levels of adrenocorticotropic hormone (ACTH) and corticosterone in rats exposed to stress. Control rats were not exposed to stress; test control rats were exposed to 4 h stress then immediately killed. In other groups, rats were exposed to the same stress followed by 30 min exposure air, dimethoxymethylbenzene (DMMB), or citralva. In the air group, IL-6 and IL-6R mRNA levels were significantly reduced and serum levels of ACTH and corticosterone significantly increased relative to the control. Exposure to DMMB significantly augmented IL-6 mRNA expression but restored that of IL-6R mRNA, did not change serum corticosterone level relative to that of the air group and significantly reduced ACTH. In comparison, citralva restored the expression of IL-6 and IL-6R mRNAs and significantly increased serum ACTH and corticosterone levels. Our results indicate that citralva enhances stress-induced activation of the hypothalamic-pituitary-adrenal axis by corticotropin-releasing hormone (CRH)-mediated stimulation of IL-6, while DMMB enhances the beneficial action of IL-6 without affecting CRH.
Komori
Teruhisa
T
Department of Psychiatry, Mie University School of Medicine, Tsu, Mie 514-8507, Japan. t-komori@clin.medic.mie-u.ac.jp
Miyahara
Satoru
S
Yamamoto
Masato
M
Matsumoto
Takuya
T
Zhang
Kai
K
Nakagawa
Masanori
M
Nomura
Sen
S
Motomura
Eishi
E
Shiroyama
Takashi
T
Okazaki
Yuji
Y
D000818:Animals; D001555:Benzene Derivatives / Q000494:pharmacology*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000378:metabolism*; D015850:Interleukin-6 / Q000235:genetics*; D008297:Male; D009570:Nitriles / Q000494:pharmacology*; D010913:Pituitary-Adrenal System / Q000187:drug effects* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D019947:Receptors, Interleukin-6 / Q000235:genetics*; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000235:genetics*
D001555:Benzene Derivatives; D015850:Interleukin-6; D009570:Nitriles; D012333:RNA, Messenger; D019947:Receptors, Interleukin-6; C054764:citralva