NPY and obesity due to melanocortin 4 receptor deficiency: Recent data also demonstrated that the release of NPY as a sympathetic neurotransmitter directly into the WAT leads to abdominal obesity with the depletion of NE in the adipose tissue [41].Moreover, the increased Y5 receptor expression in adipose tissue of obese animals and differentiated adipocytes[42–44] proved valuable cue to explain why NPY overexpression in PVN induced obesity and insulin resistance partly via Y5 receptor[45] in this experiment.