Does Your Liver Control Your Appetite?Wednesday, December 3, 2014
The answer may well be “yes”, at least if you happen to be a mouse.
In a rather exciting study by Iliana López-Soldado and colleagues from the Institute for Research in Biomedicine, Barcelona, published in DIABETES, the researchers show that increased liver glycogen content may affect appetite (measured as food intake) and otherwise have beneficial effects on metabolism.
In their experiments, the researchers used genetically modified mice, which overexpress an enzyme (PTG) resulting in increased liver glycogen.
Not only did these animals reduce their food intake when fed a high fat diet, they also did not develop the typical glucose intolerance, elevated insulin levels and fatty liver seen in normal mice on this diet.
Apart from losing weight (associated with lower leptin levels), these animals also had lower expression of neuropeptide Y (NPY) and higher expression of propiomelanocortin (POMC) in the hypothalamus.
Thus, the authors summarize their findings as follows:
:…liver glycogen accumulation caused a reduced food intake, protected against the deleterious effects of a HFD and diminished the metabolic impact of fasting. Therefore, we propose that hepatic glycogen content be considered a potential target for the pharmacological manipulation of diabetes and obesity.”
As a number of compounds exist that may do exactly that, these studies may point to a novel pathway for the pharmacological treatment of obesity – but let’s keep in mind that the road from finding in mice to effective treatments in humans is a long and thorny road.
López-Soldado I, Zafra D, Duran J, Adrover A, Calbó J, & Guinovart JJ (2014). Liver glycogen reduces food intake and attenuates obesity in a high-fat diet-fed mouse model. Diabetes PMID: 25277398