Central and Peripheral Peptides Regulating Eating Behaviour and Energy Homeostasis in Anorexia Nervosa and Bulimia Nervosa: A Literature Review

Abstract

A large body of literature suggests the occurrence of a dysregulation in both central and peripheral modulators of appetite in patients with anorexia nervosa (AN) and bulimia nervosa (BN), but at the moment, the state or trait-dependent nature of those changes is far from being clear. It has been proposed, although not definitively proved, that peptide alterations, even when secondary to malnutrition and/or to aberrant eating behaviours, might contribute to the genesis and the maintenance of some symptomatic aspects of AN and BN, thus affecting the course and the prognosis of these disorders. This review focuses on the most significant literature studies that explored the physiology of those central and peripheral peptides, which have prominent effects on eating behaviour, body weight and energy homeostasis in patients with AN and BN. The relevance of peptide dysfunctions for the pathophysiology of eating disorders is critically discussed.

The role of endocannabinoids in the control of eating disorders

“…They have predominantly anorexic action on leptin, uncoupling protein UCP, peptide YY (PYY), pancreatic polypeptide (PP polypeptide), β3-adrenergic receptors (β3 adrenergic receptor ß3-AR), Procomiomelanocortin (POMC), cholecystokinin (CCC) cholecystokinin, melanocyte stimulating hormone (MCH), melanocortin 4 receptor (MC 4-R), release hormone of corticotropin (CRH), peptide 1 similar glucagon (GLP 1), etc. However, there is a predominantly oressigenic action on the neuroptide Y (NPY), agoutirelated protein (AGRP), orexine A and B, grelin (ghrelin), opiate peptides (endorphins) and endocannabinoids [27][28][29][30][31][32][33][34].…”

Food behavior as risk factor for developing eating disorders

“…The AC often shows quantitative or qualitative modifications in function of several environmental variables like ethnic-cultural, religious, climatic; but also inside of the same individual, there are alteration of AC that show clearly how is deep-rooted his adaptation homeostatic value, directed to preservation of the constancy of internal means in site variation of environmental conditions. The neurobiological research uses an integrated interdisciplinary approach to obtain information on determinants of ED [31][32][33][34][35][36][37][38][39][40]. The eating behaviour is regulated by several factors origin both exogenouses and endogenouses.…”

“…Between these areas there is: (inferior tract of encephalic trunk and, particularly, the dorsal vagal complex) that receives and integrates the information that arrive by periphery autonomous endocrine organs and by different cerebral areas. Neuronal circuits of the mesencephalic trunk and of the thalamus interpret these information in relation to signals generated by the mechanical property of foods, that are obtained a different level of the gastrointestinal system [31][32][33][34][35][36][37][38][39][40]. The nucleus accumbens, the amygdale and the frontal cortex are responsible, instead, of more important functions that implicate the integration of cognitive information that regard the sensation of pleasantness or adversity to food.…”

“…At the hypothalamic level, in virtue of its intense vascularization and of nervous projections by the inferior tract of the encephalic trunk, it happens an exact monitoring of the haematic levels of nutriments, of hormones and of the signal that arrive by the periphery. All these information have a deep impact on the activities of the neurochemical and neuroendocrine systems of hypothalamus that, in its turn, transfers signals act to influence the behavioural and metabolic processes [31][32][33][34][35][36][37][38][39][40]. All these neuronal systems, coordinating signals of several neurotransmitters and hormones as the amino acids, amines, peptides, and other steroidal hormones, are implicate in the control process of ingestion of food and of energy balance and so of the body weight.…”

“…On this central system enters a peripheral system responsible to send of hormonal and nervous signals coming by the gastro enteric tract, by metabolic signals by adipose tissue and other generated by nutriments present in circulation. This model is made more complex by the modulating effect explained, particularly, by circulating levels of the some hormones like insulin, steroids, and thyroids hormones [31][32][33][34][35][36][37][38][39][40].…”