Smith M L, Prall B, Nandar W, Cline M A
Department of Cellular, Molecular, and Systemic Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA.
J Neuroendocrinol. 2008 Feb;20(2):220-6. doi: 10.1111/j.1365-2826.2007.01639.x. Epub 2007 Dec 14.
The melanocortin system together with other appetite-related systems plays a significant role in appetite regulation. The appetite-related effects of one such melanocortin, beta-melanocyte-stimulating hormone (MSH), are well documented in rodents; however, its effects in the avian class are not thoroughly understood. Thus, we designed a study to determine the effects of i.c.v. beta-MSH injection on food and water intake, plasma corticosterone concentration, ingestive and non-ingestive behaviours, and hypothalamic neuronal activation using Cobb-500 chicks. Chicks responded to beta-MSH-treatment with a reduction in food and water intake; however when water intake was measured independently of food intake, it was not affected. beta-MSH-treated chicks also had increased plasma corticosterone concentrations and increased c-Fos reactivity in the periventricular, paraventricular and infundibular nuclei, and the ventromedial hypothalamus; however, the lateral hypothalamus was not affected. The effect on food intake is primary because behaviours that may be competitive with food intake were not increased in beta-MSH-treated chicks. Based on these results, we conclude that beta-MSH causes anorexigenic effects that are likely primarily mediated via stimulation of satiety-related hypothalamic nuclei in broiler-type chicks.
黑皮质素系统与其他食欲相关系统共同在食欲调节中发挥重要作用。一种这样的黑皮质素，即β-促黑素细胞激素（MSH），其与食欲相关的作用在啮齿动物中已有充分记录；然而，其在鸟类中的作用尚未被完全了解。因此，我们设计了一项研究，以确定通过脑室内注射β-MSH对科宝500肉鸡的食物和水摄入量、血浆皮质酮浓度、摄食和非摄食行为以及下丘脑神经元激活的影响。雏鸡对β-MSH处理的反应是食物和水摄入量减少；然而，当独立测量水摄入量时，它不受影响。经β-MSH处理的雏鸡血浆皮质酮浓度也升高，室周核、室旁核、漏斗核和腹内侧下丘脑的c-Fos反应性增加；然而，外侧下丘脑不受影响。对食物摄入量的影响是主要的，因为在经β-MSH处理的雏鸡中，可能与食物摄入竞争的行为并未增加。基于这些结果，我们得出结论，β-MSH会导致厌食效应，这可能主要是通过刺激肉用型雏鸡中与饱腹感相关的下丘脑核来介导的。
