New functions of classical hormone α-melanophore-stimulating hormone

フォーマット:

論文

責任表示:

Tonosaki, Yoshikazu ; Sugiura, Yasuo ; Roubos, Eric W.

言語:

英語

出版情報:

弘前大学大学院医学研究科・弘前医学会, 2007-11-29

著者名:

• Tonosaki, Yoshikazu
• Sugiura, Yasuo
• Roubos, Eric W.

掲載情報:

弘前医学

ISSN:

0439-1721      

巻:

59

通号:

Supplement

開始ページ:

S202

終了ページ:

S209

バージョン:

publisher

概要:

It is well-known that α-melanophore-stimulating hormone （α-MSH） release from the amphibian parsintermedia（ PI） depends on the light condition of the animal’s background. In the present study, we present two newfunctions of … α-MSH in amphibians and mammals. In Xenopus laevis, we show that temperatures below 8 ℃ stimulateα-MSH secretion of the PI and skin darkening, with a maximum at 5 ℃, under regulation of the hypothalamus rule,independently from the illumination state of the background. The cold-induced α-MSH release of the PI was inhibited byneuropeptide-Y-producing suprachiasmatic-melanotrope-inhibiting neurons in the ventrolateral area of the suprachiasmaticnucleus but increasely in thyrotropin-releasing-hormene-containing neurons of the magnocellular nucleus. It is knownthat intracerebroventricular（ ICV） administration of a low dose of interleukin-1β（ IL-1β） induces hyperalgesia in ratand that this eff ect can be inhibited by α-MSH. To identify the part of the brain that is aff ected by hyperalgesiainducingIL-1β and the site of α-MSH concerned, we have examined Fos expression in the brain in response to ICVmicroinjection of α-MSH and/or IL-1β. Following injection of 10 pg IL-1β, hyperalgesia was induced and Fos becameexpressed in the paraventricular nucleus（ PVN） of the hypothalamus and in the arcuate nucleus（ ARC）, which containsα-MSH-producing neurons. ICV co-injection of IL-1β ・ with 30 ng α-MSH fully inhibited both hyperalgesia and Fosexpression in the PVN and the ARC. We conclude that PVN neurons are activated by hyperalgesic IL-1β and proposethat this eff ect is abolished by α-MSH released from the ARC but not from the pituitary gland. 続きを見る

URL:

http://hdl.handle.net/10129/2237