Modeling of compartment reaction delay and glucose travel time through interstitial fluid in reaction to a change of glucose concentration

Change of glucose concentration in the blood causes a change of glucose concentration in the interstitial fluid. Glucose enters the interstitial fluid from the bloodstream. Eventually, glucose leaves the interstitial fluid after some time. Its concentration in the interstitial fluid does not necessarily copy a progress of the blood concentration immediately. There is a reaction delay caused by regulatory mechanisms. In this paper, I propose two models, which demonstrate effects of the reaction delay and the glucose travel time through the interstitial fluid.