Neuropeptide Y (NPY) is a 36 amino acid peptide hormone found in the neural system and has an important role in obesity.

The main effect of Neuropeptide Y is increased food intake and decreased physical activity. It also increases the proportion of energy stored as fat and blocks nociceptive signals to the brain. In addition to its role in obesity, Neuropeptide Y has been associated with a number of other physiologic processes in the brain, including the regulation of energy balance, memory and learning, and epilepsy.

Animal studies strongly demonstrate that the stimulation of Neuropeptide Yergic activity via the administration of certain Neuropeptide Y agonists increases food intake compared to control animals. The effects of Neuropeptide Yergic activity on food intake is also demonstrated by the blockade of certain Neuropeptide Y receptors (Y1 and Y5 receptors), which expectedly inhibited Neuropeptide Yergic activity; thus, decreases food intake. For its role in obesity, an increase in Neuropeptide Y is caused by high levels of glucocorticosteriods through directly activating type II glucocorticosteriods receptors and indirectly, by abolishing the negative feedback of CRF on Neuropeptide Y synthesis and release. Meanwhile, obesity-induced insulin resistance and the mutation of the leptin receptor (ObRb) results in the abolishment of other negative feedback mechanisms to regulate Neuropeptide Yergic activity and ultimately food intake. High levels of Neuropeptide Y were also found in the cerebrospinal fluid of patients with anorexia nervosa.

The 291 bp coding sequence of the NPY gene synthesizes the pre-pro form of NPY, a 97 aa precursor peptide (see diagram below). Cleavage of the n-terminal 29 aa results in pro-NPY (69 aa), which then undergoes a further cleavage, yielding NPY 1-39 along with the 30-aa C-terminal peptide known as C-flanking peptide of NPY (CPON). NPY 1-39 is further processed to the mature form (NPY 1-36). The function of CPON is not currently understood. This EIA kit is designed to detect active NPY (1-36).

Standard, biotinylated peptide, and positive control should be stored at -20°C after arrival. Avoid multiple freeze-thaws. The remaining kit components may be stored at 4°C. Opened Microplate Wells and antibody (Item N) may be stored for up to 1 month at 2° to 8°C. Return unused wells to the pouch containing desiccant pack and reseal along entire edge.