Intracerebroventricular O-n-octanoylated ghrelin and its splice variant-induced feeding is blocked by insulin, independent of obestatin or CRF receptor, in satiated rats

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• 作者：Chih-Yen Chen ; M.D. ; Ph.D.^a ; ^{chency@vghtpe.gov.tw} ; Chang-Youh Tsai ; M.D. ; Ph.D.^b ; Wei-Jei Lee ; M.D. ; Ph.D.^c ; Wen-Jinn Liaw ; M.D. ; Ph.D.^d ; Chi-Huei Chiang ; M.D.^e ; Shung-Tai Ho ; M.D.^f ; Shou-Dong Lee ; M.D.^a
• 关键词：Acyl ghrelin ; Corticotropin-releasing factor receptor ; des-Gln14-ghrelin ; Food intake ; Insulin ; Intracerebroventricular ; Obestatin
• 刊名：Nutrition
• 出版年：2012
• 期刊代码：81_08999007
• 类别：abs
• 出版时间：July-August, 2012
• 卷：28
• 期：7-8
• 页码：812-820
• 文件大小：1030 K

摘要

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-Gln¹⁴-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-Gln¹⁴-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-Gln¹⁴-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.