Leptin, an adipocyte-derived hormone, acts on hypothalamic neurons located in the arcuate nucleus (ARC) of the hypothalamus to regulate energy homeostasis. One of the leptin-regulated neuronal subtypes in the ARC are agouti-related peptide (AgRP)-expressing neurons, which are involved in the regulation of food intake and are directly inhibited by leptin. Leptin activates the signal transducer a...

Ablation of inhibitory agouti-related protein (AgRP)-expressing neurons in the arcuate nucleus that also synthesize gamma-amino-butyric acid (GABA) and neuropeptide Y in adult mice leads to starvation within 1 week. The removal of inhibition from the AgRP neurons onto neighboring proopiomelanocortin neurons and their common postsynaptic neurons is predicted to stimulate melanocortin signaling, ...

Agouti-related protein encodes a neuropeptide that stimulates food intake. Agrp expression in the brain is restricted to neurons in the arcuate nucleus of the hypothalamus and is elevated by states of negative energy balance. The molecular mechanisms underlying Agrp regulation, however, remain poorly defined. Using a combination of transgenic and comparative sequence analysis, we have previousl...

Agouti-related peptide (AgRP), the endogenous antagonist to the melanocortin 3 and 4 receptors, elicits robust hyperphagia and weight gain in rodents when administered directly into the central nervous system. The relative influence of AgRP to cause weight gain in rodents partially depends on the activity level of the melanocortin agonist-producing proopiomelanocortin neurons. Both proopiomelan...

Neuropeptide Y (NPY) and the endogenous melanocortin receptor antagonist, agouti gene-related protein (AGRP), coexist in the arcuate nucleus, and both exert orexigenic effects. The present study aimed primarily at determining the brain distribution of AGRP. AGRP mRNA-expressing cells were limited to the arcuate nucleus, representing a major subpopulation (95%) of the NPY neurons, which also was...

Obesity is a chronic condition resulting from a long-term pattern of poor diet and lifestyle. Long-term consumption of high-fat diet (HFD) leads to persistent activation and leptin resistance in AgRP neurons in the arcuate nucleus of the hypothalamus (ARH). Here, for the first time, we demonstrate acute effects of HFD on AgRP neuronal excitability and highlight a critical role for diet composit...

Agouti-related peptide (AgRP) is a receptor antagonist of central nervous system (CNS) melanocortin receptors and appears to have an important role in the control of food intake since exogenous CNS administration in rats and overexpression in mice result in profound hyperphagia and weight gain. Given that AgRP is heavily colocalized with neuropeptide Y (NPY) and that orexigenic effects of NPY d...

melanocortin- 4 receptor (mc4r) and agouti- related peptide (agrp) are involved in energy homeostasis in rats. according to mc4r and agrp effects on luteinizing hormone (lh) secretion, they may influence the estrous cycle of rats. therefore, the aim of this study was to investigate the expression of mc4r and agrp mrnas at different stages of estrous cycle in the rat’s hypothalamus. the estrous ...

OBJECTIVE Food intake and whole-body energy homeostasis are controlled by agouti-related protein (AgRP) and pro-opiomelanocortin (POMC) neurons located in the arcuate nucleus of the hypothalamus. Key energy sensors, such as the AMP-activated protein kinase (AMPK) or sirtuin 1 (SIRT1), are essential in AgRP and POMC cells to ensure proper energy balance. In peripheral tissues, the transcriptiona...

Melanocortin- 4 receptor (MC4R) and agouti- related peptide (AgRP) are involved in energy homeostasis in rats. According to MC4R and AgRP effects on luteinizing hormone (LH) secretion, they may influence the estrous cycle of rats. Therefore, the aim of this study was to investigate the expression of MC4R and AgRP mRNAs at different stages of estrous cycle in the rat's hypothalamus. The estrous ...