Li Muyao, Vizzard Margaret A, Jaworski Diane M, Galbraith Richard A
Department of Medicine, University of Vermont, C209 Given Bldg., 89 Beaumont Ave., Burlington, Vermont 05405, USA.
J Appl Physiol (1985). 2006 Jun;100(6):1983-91. doi: 10.1152/japplphysiol.01169.2005. Epub 2006 Feb 9.
Administration of cobaltic protoporphyrin IX (CoPP) into the third ventricle of the brain by intracerebroventricular injection in rodents is known to result in transient hypophagia and remarkably prolonged weight loss. The mechanism of action of CoPP in eliciting these effects is unknown. It is known that nitric oxide plays a role in food intake and that the hyperphagia that results from a wide variety of genetic, physiological, and pharmacological stimuli can be blocked by the administration of inhibitors of the enzyme nitric oxide synthase (NOS). We demonstrate that intracerebroventricular administration of compounds that alter nitrergic tone can also change food ingestion and weight gain patterns in normophagic rats. We also demonstrate that CoPP decreases NOS activity but that it paradoxically increases neuronal NOS transcript expression and increases neuronal NOS protein content on Western blotting.
通过向啮齿动物脑室内注射钴原卟啉IX（CoPP）至脑第三脑室，已知会导致短暂性摄食减少和显著延长的体重减轻。CoPP引发这些效应的作用机制尚不清楚。已知一氧化氮在食物摄入中起作用，并且多种遗传、生理和药理刺激所导致的食欲亢进可通过给予一氧化氮合酶（NOS）抑制剂来阻断。我们证明，向脑室内注射改变一氧化氮能张力的化合物也可改变正常摄食大鼠的食物摄取和体重增加模式。我们还证明，CoPP可降低NOS活性，但自相矛盾的是，它会增加神经元型NOS转录本表达，并在蛋白质免疫印迹法检测中增加神经元型NOS蛋白含量。
