Modeling insulin's negative feedback loop
Author(s): John Cumbers
Affiliations: Brown University
Contact:email: John at brown point edu
Keywords: 'insulin' 'modeling' 'model' 'negative feedback'
Models are used to make predictions about biological systems. When making a model some simplifications must be made to make the problem tractable. A negative feedback mechanism has recently been shown to regulates insulin receptor levels and a model of the insulin-signaling pathway is presented here using differential equations. The output displays the key characteristics of this negative feedback loop under two different inputs. When fed a constant input of nutrients (a typical diet in the USA), the model mimics reduced receptor number and reduced sensitivity, which would in turn lead to higher glucose levels and over production of insulin by the pancreas (a pre-diabetic state). If pancreatic beta cell burn out is the pathology of diabetes, then when no more insulin can be produced the patient develops type II diabetes. However, when fed a cyclic input of nutrients (a more natural diet evolved from a hunter gatherer) the model exhibits normal cyclic output of insulin and no diabetes. The model and results will be presented.