NPY and obesity due to melanocortin 4 receptor deficiency: In rats with diet-induced obesity, long-term administration of a GLP-1R agonist regulates neuronal expression of cocaine- and amphetamine-regulated transcript (CART) and neuropeptide Y (NPY)/Agouti-related protein (AgRP) (increased CART and reduced the expression of NPY, AgRP) in the arcuate nucleus and decreases food intake and body weight [14].