Geelissen S M E, Swennen Q, Geyten S Van der, Kühn E R, Kaiya H, Kangawa K, Decuypere E, Buyse J, Darras V M
Laboratory of Comparative Endocrinology, Zoological Institute, K.U. Leuven, Naamsestraat 61, 3000 Leuven, Belgium.
Domest Anim Endocrinol. 2006 Feb;30(2):108-16. doi: 10.1016/j.domaniend.2005.06.005. Epub 2005 Jul 18.
Ghrelin injection, either centrally or peripherally strongly stimulates feeding in human and rodents. In contrast, centrally injected ghrelin inhibits food intake in neonatal chickens. No information is available about the mechanism and its relationship with energy homeostasis in chicken. Since ghrelin is predominantly produced in the stomach, we investigated the effect of peripherally injected ghrelin (1 nmol/100g body weight) on food intake and energy expenditure as measured in respiratory cells by indirect calorimetry for 24h in one-week-old chickens. Plasma glucose, triglycerides, free fatty acids, total protein and T(3) were measured in a separate experiment until 60 min after injection. Food intake decreased until at least 1h after intravenous ghrelin administration. The respiratory quotient (RQ) in ghrelin-injected chickens was reduced until 14 h after administration whereas plasma glucose and triglycerides concentrations were not altered. Free fatty acids and total protein levels also remained unchanged. Ghrelin did not influence heat production and this was supported by the absence of changes in plasma T(3) levels when compared to the control values. In conclusion, peripheral ghrelin reduces food intake as well as RQ and might influence the type of substrate (macronutrient) that is used as metabolic fuel.
无论是中枢注射还是外周注射，胃饥饿素均能强烈刺激人和啮齿动物进食。相比之下，中枢注射胃饥饿素会抑制新生雏鸡的食物摄入。目前尚无关于鸡体内该机制及其与能量稳态关系的信息。由于胃饥饿素主要在胃中产生，我们研究了外周注射胃饥饿素（1 nmol/100g体重）对一周龄雏鸡食物摄入量和能量消耗的影响，采用间接测热法在呼吸细胞中测量24小时。在另一个实验中，测量注射后60分钟内的血浆葡萄糖、甘油三酯、游离脂肪酸、总蛋白和T(3)。静脉注射胃饥饿素后，食物摄入量至少在1小时内减少。注射胃饥饿素的雏鸡的呼吸商（RQ）在给药后14小时内降低，而血浆葡萄糖和甘油三酯浓度未改变。游离脂肪酸和总蛋白水平也保持不变。胃饥饿素不影响产热，与对照值相比，血浆T(3)水平没有变化也证明了这一点。总之，外周胃饥饿素会减少食物摄入量和呼吸商，并可能影响用作代谢燃料的底物（常量营养素）类型。
