Cui Zhenzhong, Smith Adam S
Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
J Biol Methods. 2019 Jul 4;6(3):e116. doi: 10.14440/jbm.2019.288. eCollection 2019.
Agouti-related peptide (AgRP) neurons of the hypothalamus play a role in hunger-triggered food intake, stability of body weight, and long-term energy balance. A recent study showed that activation of the G-linked G protein-coupled receptors (GCPR) expressed by hypothalamic AgRP neurons promotes a sustained increase in food intake. Enhanced AgRP release has been the postulated underlying mechanism. Here, we confirmed that activation of G-coupled receptors expressed by AgRP neurons in the arcuate nucleus (ARC) of the hypothalamus, which is the primary brain region for the synthesis and release of AgRP, leads to increased release of AgRP in the paraventricular nucleus of the hypothalamus (PVN). We were unable to confirm changes in AgRP expression or intracellular content using traditional histological techniques. Thus, we developed an assay to measure AgRP in the extracellular fluid in the brain using large molecular weight cut-off microdialysis probes. Our technique enables assessment of brain AgRP pharmacokinetics under physiological conditions and in response to specific pharmacological interventions designed to modulate AgRP signaling.
下丘脑的刺鼠相关肽（AgRP）神经元在饥饿引发的食物摄入、体重稳定和长期能量平衡中发挥作用。最近的一项研究表明，下丘脑AgRP神经元表达的G蛋白偶联受体（GCPR）的激活会促进食物摄入量的持续增加。增强的AgRP释放被认为是潜在机制。在此，我们证实，下丘脑弓状核（ARC）中AgRP神经元表达的G偶联受体的激活会导致下丘脑室旁核（PVN）中AgRP释放增加，ARC是合成和释放AgRP的主要脑区。我们无法使用传统组织学技术确认AgRP表达或细胞内含量的变化。因此，我们开发了一种使用大分子量截留微透析探针测量脑中细胞外液中AgRP的测定方法。我们的技术能够在生理条件下以及响应旨在调节AgRP信号传导的特定药理干预时评估脑AgRP的药代动力学。
