Intentando conocer los mecanismos de control del peso corporal entendemos mejor cómo nos reproducimos: a propósito del neuropéptido Y

Neuropeptide Y (NPY) is a polypeptide containing 36 amino acids and its structure is similar in humans and rats. NPYproducing neurons are located in the arcuate nucleus of the hypothalamus and NPY fibers project to hypothalamic centers involved in the control of food intake. Intracerebroventricular administration of NPY increases food intake. The actions of NPY are mediated by at least 5 subtypes of receptors. NPY is secreted to the hypothalamic-pituitary portal circulation and participates in the control of reproductive function. NPY is involved in puberty onset, control of luteinizing hormone-releasing hormone (LHRH) secretion and pituitary responsiveness to LHRH. In addition, NPY is involved in the control of prolactin (PRL) release and gonadal function. The effects of this peptide depend on the steroid milieu, route of administration, dosage, and treatment duration. The use of specific knock-out animals and the existence of specific agonists/antagonist for the various receptors will improve our understanding of the functional role of these receptors. In this sense, it is noticeable that PYY3-36, a hormone that is structurally related to NPY, is an agonist of receptor subtypes Y2 and Y5 and is secreted from the gastrointestinal tract. PYY3-36 stimulates LH and PRL secretion.