SummaryRecent biochemical and physiological work has brought evidence of two important groups of corticosterones. The first group characterised by the presence of an O atom on the eleventh C regulates directly carbohydrate metabolism disturbances.Action of the second group (without O atom on C eleven) is directed chiefly against disbalance of plasma ions and their renal excretion. They influence carbohydrate metabolism only indirectly by favouring intestinal absorption of glucides.Dissociated action of different corticosterones in Addison’s disease has been illustrated by very few clinical cases. Only Thorn, de la Balze and Mc Lean have reported three cases of patients who died of hypoglycemia in spite of a long lasting treatment with desoxycorticosterone acetate.Two cases reported here have been closely followed from 1938 during six and seven years, receiving respectively 13 and 18 subcutaneous D. C. S. pellet implants. First case presented severe hypoglycemia on two occasions. Interruption of D. C. S. treatment was responsible for the first hypoglycemic state (1939). Immediate injection of total cortical extracts and glucose quickly restored the situation back to normal.It is actually well known that sterones of the first group are only present in those total aqueous extracts. The second crisis occured five years later. Although blood glucose level was quickly normalised by glucose injections, the patient died in hyperthermic state; as total extracts were not available at that time, strong doses of D. C. S. were used and proved to be uneffective against acute suprarenal insufficiency.Second patient showed no tendency to hypoglycemia even during two severe acute Addisonian crisis, observed before D. C. S. treatment was initiated (1939). Crisis did not recure during the next six years of continuous treatment, but in 1945, routine blood glucose examinations revealed tendency to hypoglycemia after prolonged fasting as well as after absorption of glucose (late hypoglycemia). Increased D. C. S. administration brought partial improvement of the hyperglycemic curve, and reduced both late and fasting hypoglycemia. The effect is believed to result from better glucose intestinal absorption. D. C. S. treatment should not be discarded under influence of recent physiological publications, as sterones of the first group have not yet been synthetized and total extracts remain expensive and must be injected daily. Such extracts are especially usefull in acute crisis not reacting to D. C. S. which however does remain the most practical basic treatment forpreventionof acute episodes. Interest of case two is to show anindirectaction of D. C. S. on blood glucose level and glucose tolerance test notwithstanding its principal effectiveness on ionic disbalance.