text: Insulin secretion results in positive feedback in different ways. Firstly, insulin increases the uptake of glucose from blood by the translocation and exocytosis of GLUT4 storage vesicles in the muscle and fat cells. Secondly, it promotes the conversion of glucose into triglyceride in the liver, fat, and muscle cells. Finally, the cell will increase the rate of glycolysis within itself to break glucose in the cell into other components for tissue growth purposes.
  An example of positive feedback mechanism in the insulin transduction pathway is the activation of some enzymes that inhibit other enzymes from slowing or stopping the insulin transduction pathway which results in improved intake of the glucose.
  One of these pathways, involves the PI(3)K enzyme (Phosphoinositide 3-kinase). This pathway is responsible for activating glycogen, lipid-protein synthesis, and specific gene expression of some proteins which will help in the intake of glucose.
  Different enzymes control this pathway. Some of these enzymes constrict the pathway causing a negative feedback like the GSK-3 pathway. Other enzymes will push the pathway forward causing a positive feedback like the AKT and P70 enzymes.
  When insulin binds to its receptor, it activates the glycogen synthesis by inhibiting the enzymes that slow down the PI(3)K pathway such as PKA enzyme. At the same time, it will promote the function of the enzymes that provide a positive feedback for the pathway like the AKT and P70 enzymes. The inactivation of the enzymes that stop the reaction and activating of enzymes that provide a positive feedback will increase glycogen, lipid & protein syntheses and promote glucose intake.
  ([http://www.nature.com/nature/journal/v414/n6865/fig_tab/414799a_F2.html#figure-title Image to help explain the function of the proteins mentioned above in the positive feedback.])