The neuropeptides concerned with feeding behavior are involved in this complex controlling system, of which the anorexigenic neuropeptide like proopiomelanocortin
(POMC) and orexigenic neuropeptide like Neuropeptide Y (NPY) play important roles in the regulation of food intake and energy balance (Bazhan and Zelena, 2013).
Neuropeptide Y-mediated inhibition of proopiomelanocortin
neurons in the arcuate nucleus shows enhanced desensitization in ob/ob mice.
In the normal pituitary, ACTH is made byproteolytic processing of the precursor molecule proopiomelanocortin
. When processing is faulty, as occurs in some cases of ectopic production of ACTH by tumors, a big form of ACTH is formed.
antigens are commonly detected in melanomas, showing more intense and diffuse immunocytochemical stain in VGP.
Thus, its deficiency leads to insufficient activation of several hormones including proinsulin, proopiomelanocortin
, pro-thyrotropin-releasing hormone, pro-glucagon, and pro-gonadotropin-releasing hormone (1,2).
At variance with the idea of a possible relationship between LCN-2 upregulation and the anorexigenic effects induced by the overactivity of the melanocortin 4 receptor(MC4R-) pathway [97, 98], pioglitazone treatment failed to stimulate an increase of body weight in ALS patients and in SOD1 mice , a lack of effect described by the hypothesis of defective melanocortin system and downregulation of proopiomelanocortin
(POMC) neurons in ALS.
The anorexigenic response is mediated by proopiomelanocortin
(POMC) neurons, and the orexigenic response is mediated by agouti-related protein (AgRP) expressing neurons .
In the next section, we will describe evidence of the involvement of peptides derived from prohormone proopiomelanocortin
(POMC) and the ghrelin and leptin hormones as potential central modulators of microglia-dependent inflammation in a context of positive energy balance.
Age-related decrease in proopiomelanocortin
gene expression in the arcuate nucleus of the male rat brain.
Leptin, an anorexogenic adipokine, stimulates the production of proopiomelanocortin
products, which bind to MC4R, resulting in decreased food intake and increased energy expenditure (86).
Human small cell lung cancer cell lines expressing the proopiomelanocortin
gene have aberrant glucocorticoid receptor function.
Fear prompts the release of corticotropin-releasing hormone (CRH), which in turn stimulates the release of proopiomelanocortin
(POMC), a large molecule that is broken up into several parts including adrenocorticotropic hormone (ACTH), which is responsible for the familiar "fight or flight" response, and beta-endorphin, which may have the survival advantage of numbing pain if the organism is attacked.