TY - JOUR
T1 - Intracerebroventricular O-n-octanoylated ghrelin and its splice variant-induced feeding is blocked by insulin, independent of obestatin or CRF receptor, in satiated rats
AU - Chen, Chih Yen
AU - Tsai, Chang Youh
AU - Lee, Wei Jei
AU - Liaw, Wen Jinn
AU - Chiang, Chi Huei
AU - Ho, Shung Tai
AU - Lee, Shou Dong
N1 - Funding Information:
This work was supported by grants from National Science Council ( NSC 95-2320-B-075-007 - and NSC 96-2320-B-010-037 - to C.Y.C.) and partly by Academia Sinica ( IBMS-CRC95-V01 to C.Y.C.), Taiwan. The authors thank Tiffany C. Lee for her secretarial assistance in manuscript editing. The authors thank the help from Chi Chin-Wen, Ph.D., Hung Mei-Whey, M.S., Miss Lee Chia-Jung, and the Clinical Research Core Laboratory, Taipei Veterans General Hospital.
PY - 2012/7
Y1 - 2012/7
N2 - Objective: The purpose of this study was to investigate the impact of intracerebroventricular (ICV) injection of the two endogenous forms of acyl ghrelin, O-n-octanoylated ghrelin and des-Gln 14-ghrelin, on feeding behavior, as well as their interactions with insulin, obestatin, and corticotropin-releasing factor receptor (CRF-R) antagonist in the forebrain to influence food intake. Methods: We examined the food intake in conscious, freely fed rats, which were chronically implanted with ICV catheters. Results: O-n-octanoylated ghrelin and des-Gln 14-ghrelin (0.1 nmol/rat) were equally potent in stimulating food intake in freely fed rats, up to 8 h after ICV injection (P < 0.05). In contrast, ICV administration of insulin (8 mU/rat), obestatin (2 nmol/rat), and astressin (2 nmol/rat), a specific CRF-R antagonist, did not modify feeding in freely fed rats. Furthermore, pretreatment with ICV insulin (P < 0.01), but not obestatin or astressin, at the abovementioned dose, blocked central acyl-ghrelin-induced hyperphagic effects. Conclusion: ICV O-n-octanoylated ghrelin and its splice variant, des-Gln 14-ghrelin, are equally potent to elicit food intake in freely fed rats, while these feeding-stimulating effects are opposed by insulin, but independent of obestatin and endogenous CRF-R in the forebrain.
AB - Objective: The purpose of this study was to investigate the impact of intracerebroventricular (ICV) injection of the two endogenous forms of acyl ghrelin, O-n-octanoylated ghrelin and des-Gln 14-ghrelin, on feeding behavior, as well as their interactions with insulin, obestatin, and corticotropin-releasing factor receptor (CRF-R) antagonist in the forebrain to influence food intake. Methods: We examined the food intake in conscious, freely fed rats, which were chronically implanted with ICV catheters. Results: O-n-octanoylated ghrelin and des-Gln 14-ghrelin (0.1 nmol/rat) were equally potent in stimulating food intake in freely fed rats, up to 8 h after ICV injection (P < 0.05). In contrast, ICV administration of insulin (8 mU/rat), obestatin (2 nmol/rat), and astressin (2 nmol/rat), a specific CRF-R antagonist, did not modify feeding in freely fed rats. Furthermore, pretreatment with ICV insulin (P < 0.01), but not obestatin or astressin, at the abovementioned dose, blocked central acyl-ghrelin-induced hyperphagic effects. Conclusion: ICV O-n-octanoylated ghrelin and its splice variant, des-Gln 14-ghrelin, are equally potent to elicit food intake in freely fed rats, while these feeding-stimulating effects are opposed by insulin, but independent of obestatin and endogenous CRF-R in the forebrain.
KW - Acyl ghrelin
KW - Corticotropin-releasing factor receptor
KW - Des-Gln -ghrelin
KW - Food intake
KW - Insulin
KW - Intracerebroventricular
KW - Obestatin
UR - http://www.scopus.com/inward/record.url?scp=84862181584&partnerID=8YFLogxK
U2 - 10.1016/j.nut.2011.11.021
DO - 10.1016/j.nut.2011.11.021
M3 - Article
C2 - 22465905
AN - SCOPUS:84862181584
SN - 0899-9007
VL - 28
SP - 812
EP - 820
JO - Nutrition
JF - Nutrition
IS - 7-8
ER -
