The regulatory mechanisms that come into play in response to a sharp decline of the blood sugar concentration, restoring its equilibrium (hypoglycemia responsiveness), and the impairment of these mechanisms in spontaneous hypoglycemia or induced hypoglycemia (hypoglycemia unresponsiveness) are not clearly understood. However, it has been established that the responsiveness of certain organs or systems seems to be of primary importance in such homeostasis. These are (1) the sympathico-medullo-adrenal system, (2) the anterior pituitary and the adrenal cortex, and (3) the glycogenolytic responsiveness of the liver.
Hypoglycemia responsiveness has been investigated in man and experimental animal, by studying insulin sensitivity, in the sense of measuring the rate of decline of the glucose content in the blood after a given test dose of insulin. A number of methods have been designed for the study of the kinetics of blood sugar elimination from the blood stream, and modifications of these have appeared in