Accepted Preprint first posted online on 7 April 2009
Journal of Endocrinology 2009;201:341.
Journal of Endocrinology (2009) In press
DOI: 10.1677/JOE-08-0374
© 2009 Society for Endocrinology
Ghrelin suppresses noradrenaline release in the brown adipose tissue of rats
Asuka Mano,
Hisayuki Ohata,
Azusa Iwasaki,
Takahiro Nemoto and
Tamotsu Shibasaki
A Mano, Physiology, Nippon Medical School, Tokyo, 113-8602, Japan
H Ohata, Physiology, Nippon Medical School, Tokyo, Japan
A Iwasaki, Physiology, Nippon Medical School, Tokyo, Japan
T Nemoto, Physiology, Nippon Medical School, Tokyo, Japan
T Shibasaki, Physiology, Nippon Medical School, Tokyo, Japan
Correspondence: Asuka Mano, Email: asuka{at}nms.ac.jp
TTo clarify the role of ghrelin in the regulatory mechanism of energy metabolism, we analyzed the effects of centrally and peripherally administered ghrelin on noradrenaline release in the brown adipose tissue (BAT) of rats using a microdialysis system. Intracerebroventricular (icv) administration of ghrelin at a dose of 500 pmol suppressed noradrenaline release in BAT, and microinjection of ghrelin (50 pmol) into the paraventricular nucleus (PVN) or arcuate nucleus (ARC) of the hypothalamus also suppressed noradrenaline release in BAT. In addition, intravenously (iv) administered ghrelin (30 nmol) suppressed noradrenaline release in BAT, and this suppression was blocked by a vagotomy. Neither icv nor iv administration of des-acyl ghrelin, which does not bind to growth hormone secretagogue receptor type 1a (GHS-R1a), affected noradrenaline release in BAT. These results indicate that ghrelin increases energy storage by suppressing the activity of the sympathetic nerve innervating BAT. It seems that the PVN and ARC, which express GHS-R1a, are the sites of action of ghrelin in the brain and that the action of peripheral ghrelin on the sympathetic nerve activity innervating BAT is mediated by the vagal nerve, which also expresses GHS-R1a.
Copyright © 2009 by the Society for Endocrinology.