Gaskin F Spencer, Farr Susan A, Banks William A, Kumar Vijaya B, Morley John E
Department of Internal Medicine, Geriatric Research Education and Clinical Center, VA Medical Center, Division of Geriatric Medicine, St. Louis University School of Medicine, 915 N. Grand Blvd., St. Louis, MO 63106, USA.
Peptides. 2003 Jun;24(6):913-8. doi: 10.1016/s0196-9781(03)00160-8.
Ghrelin is a newly discovered gastric peptide, which has orexigenic effects. Ghrelin is the endogenous ligand for the growth hormone secretagogue receptor and stimulates growth hormone and gastrointestinal motility. We have previously shown that nitric oxide (NO) plays an important role as a mediator of feeding induced by a variety of neuropeptides. This raises the question of whether ghrelin's effects are NO dependent. Here, we first determined that intracerebroventricular administration of 100 ng of ghrelin significantly increased food intake in satiated mice. We next examined the effects of N(omega)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, on ghrelin-induced increase in food intake. A subthreshold dose (12.5mg/kg; SC) of L-NAME significantly blocked the ghrelin-induced increase in food intake. Ghrelin administration increased the levels of nitric oxide synthase in the hypothalamus. This supports the hypothesis that nitric oxide is a central regulator of food consumption.
胃饥饿素是一种新发现的胃肽，具有促食欲作用。胃饥饿素是生长激素促分泌素受体的内源性配体，可刺激生长激素和胃肠蠕动。我们之前已经表明，一氧化氮（NO）作为多种神经肽诱导进食的介质发挥重要作用。这就提出了一个问题，即胃饥饿素的作用是否依赖于NO。在此，我们首先确定，向脑室注射100 ng胃饥饿素可显著增加饱足小鼠的食物摄入量。接下来，我们研究了一氧化氮合酶抑制剂N（ω）-硝基-L-精氨酸甲酯（L-NAME）对胃饥饿素诱导的食物摄入量增加的影响。L-NAME的阈下剂量（12.5mg/kg；皮下注射）可显著阻断胃饥饿素诱导的食物摄入量增加。注射胃饥饿素可增加下丘脑一氧化氮合酶的水平。这支持了一氧化氮是食物消耗的中枢调节因子这一假说。
