Chronic intracerebroventricular administration of relaxin-3 increases body weight in rats.
Bolus-administered intracerebroventricular (ICV) relaxin-3 has been reported to increase feeding. In this study, to examine the role of relaxin-3 signaling in energy homeostasis, we studied the effects of chronically administered ICV relaxin-3 on body weight gain and locomotor activity in rats. Two groups of animals received vehicle or relaxin-3 at 600 pmol/head/day, delivered with Alzet osmotic minipumps. In animals receiving relaxin-3, food consumption and weight gain were statistically significantly higher than those in the vehicle group during the 14-day infusion. During the light phase on days 2 and 7 and the dark phase on days 3 and 8, there was no difference in locomotor activity between the two groups. Plasma concentrations of leptin and insulin in rats chronically injected with relaxin-3 were significantly higher than in the vehicle-injected controls. These results indicate that relaxin-3 up-regulates food intake, leading to an increase of body weight and that relaxin-3 antagonists might be candidate antiobesity agents.
Hida
Takayuki
T
Laboratory of Seeds Finding Technology, Eisai Co., Ltd., Tsukuba, Ibaraki, Japan.
Takahashi
Eiki
E
Shikata
Kodo
K
Hirohashi
Tomoko
T
Sawai
Toru
T
Seiki
Takashi
T
Tanaka
Hirokazu
H
Kawai
Takatoshi
T
Ito
Osamu
O
Arai
Toru
T
Yokoi
Akira
A
Hirakawa
Tetsuya
T
Ogura
Hiroo
H
Nagasu
Takeshi
T
Miyamoto
Norimasa
N
Kuromitsu
Junro
J
D000818:Animals; D001835:Body Weight / Q000187:drug effects* / Q000502:physiology; D004435:Eating / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007276:Injections, Intraventricular; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000502:physiology; D009765:Obesity / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000008:administration & dosage; D012065:Relaxin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects
D007328:Insulin; D020738:Leptin; D009419:Nerve Tissue Proteins; C480238:RLN3 protein, human; C466742:RLN3 protein, rat; D011994:Recombinant Proteins; D012065:Relaxin