Nicotine suppresses energy storage through activation of sympathetic outflow to brown adipose tissue via corticotropin-releasing factor type 1 receptor.
Nicotine is known to stimulate energy expenditure, although the precise mechanism is unclear. To clarify the involvement of corticotropin-releasing factor (CRF) in the mechanism by which nicotine increases energy expenditure, the effect of intraperitoneal injection of nicotine (0.1 or 0.5mg/kg) on the release of noradrenaline (NA), a stimulator of thermogenesis, in brown adipose tissue (BAT) important for energy expenditure was examined in rats. We also examined the effects of CRF receptor subtype antagonists on the nicotine-induced change in BAT NA release. Nicotine significantly increased BAT NA release at a dose of 0.5mg/kg, and the increase was completely blocked by antalarmin, a CRF type 1 receptor antagonist, but not by antisauvagine-30, a CRF type 2 receptor antagonist. These results suggest that nicotine increases energy expenditure by activating BAT function, and that CRF type 1 receptors are involved in the mechanism by which nicotine affects energy balance.
Department of Physiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8602, Japan. asuka@nms.ac.jp
Asuka
A
Mano-Otagiri
Azusa
A
Iwasaki-Sekino
Hisayuki
H
Ohata
Keiko
K
Arai
Tamotsu
T
Shibasaki
D002001:Adipose Tissue, Brown / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism; D000818:Animals; D004734:Energy Metabolism / Q000187:drug effects*; D007274:Injections, Intraperitoneal; D008297:Male; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D011743:Pyrimidines / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018019:Receptors, Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D000099052:CRF Receptor, Type 1
D011743:Pyrimidines; D011758:Pyrroles; D018019:Receptors, Corticotropin-Releasing Hormone; C103016:antalarmin; D000099052:CRF Receptor, Type 1; D009538:Nicotine; D009638:Norepinephrine