Pituitary Adenylate Cyclase-Activating Peptide in the Central Amygdala Causes Anorexia and Body Weight Loss via the Melanocortin and the TrkB Systems
2015
Abstract
Growing evidence suggests that the pituitary adenylate cyclase-activating peptide (PACAP)/PAC1 receptor system represents one of the main regulators of the behavioral, endocrine, and autonomic responses to stress. Although induction of anorexia is a well-documented effect of PACAP, the central sites underlying this phenomenon are poorly understood. The present studies addressed this question by examining the neuroanatomical, behavioral, and pharmacological mechanisms mediating the anorexia produced by PACAP in the central nucleus of the amygdala (CeA), a limbic structure implicated in the emotional components of ingestive behavior. Male rats were micro-infused with PACAP (0-1??g/rat) into the CeA and home-cage food intake, body weight change, micro-structural analysis of food intake and loco motor activity were assessed. Intra-CeA (but not intra-basolateral amygdala) PACAP dose-dependently induced anorexia and body weight loss without affecting loco motor activity. PACAP-treated rats ate smaller meals of normal duration. This revealed that PACAP slowed feeding within meals by decreasing the regularity and maintenance of feeding from pellet-to-pellet; postprandial satiety was unaffected. Intra-CeA PACAP-induced anorexia was blocked by co-infusion of either the melanocortin receptor 3/4 antagonist SHU 9119 or the tyrosine kinase B (TrKB) inhibitor k-252a, but not the CRF receptor antagonist D-Phe-CRF(12-41). These results indicate that the CeA is one of the brain areas through which the PACAP system promotes anorexia and that PACAP preferentially lessens the maintenance of feeding in rats, effects opposite to those of palatable food. We also demonstrate that PACAP in the CeA exerts its anorectic effects via local melanocortin and the TrKB systems, and independently from CRF.
How long does it take for PACAP to take effect? I am interested on the body weight loss part as my BMI reflected that I am obese (we had an annual company physical exam lately and it scared the hell out of me). My other question might sound stupid but was this already tested to humans?
Thank you for sharing this, Semin. I am actually researching on the effects of PACAP because of my sister. I find it amusing and a bit threatening at the same time because she is denying the anorexic effect. It is very alarming on her end, she looks really thin and I am worried.
I think denial is a big issue when it comes to anything such as anorexia, as the person themselves, can't see the daneage they are doibg to themselves. It's like they're seeing a totally different person in the mirror to what others are seeing.
I think being anorexic is a state of mind. I know that peptides would help appetite loss but anorexia? Isn't that too much? If it is so, then this should not be recommended at all most especially to those whose goal are to have big bulks of muscles all around them.
Youa are right about that @lizknows. I think many people start using peptides without having sufficient information on the same. Those are the same ones who are in denial of the effects taking it has on them.
Peptides had been a big help! I lost weight and gained the body structure that I have always wanted for myself. However, I never experienced anorexia. I also know a lot of men and women who use peps, but none of them is suffering from anorexia as well. So, I guess, this is not true.
Peptide is a great product for anyone wanting to lose weight or maintain weight. But this study provides information that peptide use may be associated with anorexia. And that's really conflicting and scary. I think anorexia is a serious condition and should be dealt with properly. Furthermore, people with previous mental problems should consult a doctor before taking in any medications.
IMO, I think anorexia develops since people will no longer be contented with the weight loss and will start thinking that it's still not enough, until they will reach the point that they will no longer eat and develop an eating disorder.
Yes, peptides can cause weight loss. It is even one of the biggest reasons as to why many people are lured to use it. However, I disagree that it causes anorexia. Probably, there is something wrong with someone's diet if they are going through aneroxia.
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